A powerful parliamentary committee tasked with reviewing files relating to Peter Mandelson’s appointment as US ambassador has revealed that the government is withholding his vetting file despite not having the authority to do so.

In an extraordinary intervention, the intelligence and security committee (ISC) has criticised the government over its handling of the release of Mandelson-related papers and in effect accused ministers failing to comply with parliament’s will.

In February, parliament passed a motion known as a humble address requiring the government to publicly release all papers relevant to Mandelson’s appointment.

The government has repeatedly said it will comply with the motion, which ordered that any documents that could be prejudicial to national security or international relations should first be reviewed by the ISC.

The group of senior MPs and peers have been reviewing the files to decide which, if any, should be redacted or withheld from public release. In a statement on Friday, the ISC said it has completed its work but that it had not been provided all the relevant documents.

“The committee has been told that certain documents are being withheld from the process,” the statement said. It said “the prime example” of documents being withheld was “a vetting file held by UK Security Vetting” (UKSV), the agency that in January 2025 recommended Mandelson’s security clearance should be denied.

The following day, the Foreign Office’s then permanent secretary, Olly Robbins, granted Mandelson his “developed vetting” status anyway, paving the way for him to take up his post in Washington the following month.

Robbins, who has since been sacked by Keir Starmer, has said officials were under pressure from Downing Street to get Mandelson to Washington, but said the pressure did not influence his decision to grant him clearance. Robbins has said he granted clearance without viewing the vetting file, relying instead on an oral briefing from an official who had not seen it either.

In its statement, the committee said it did not believe the terms of the humble address allowed “for any documents to be withheld from parliament”, adding: “While government may believe that there is good reason to withhold certain documents, it does not currently have the authority to so do.”

Starmer’s government is now expected to face intense pressure to explain why it has chosen to withhold the vetting file.

The prime minister’s decision to appoint Mandelson as ambassador to the US in December 2024 has cast a shadow over his premiership and led to calls for his resignation prior to Labour’s poor showing in the local elections.

One of his chief rivals, the former health secretary Wes Streeting, also faces questions over his proximity to Mandelson, whom some have described as his mentor.

The ISC also criticised the government’s approach to redacting documents that have been released. Under the terms of the humble address, documents can be redacted on the grounds of international relations and national security. However, the government has said it is making additional redactions, such as removing the personal data of third parties or information deemed commercially sensitive.

The ISC said it did not believe the humble address provided the government with scope for such redactions, and warned that it believed the redactions were being applied “far too broadly”.

It said the government needed to return to parliament to seek permission to make further redactions. It noted that no body had been commissioned to review the additional redactions made by the government.

In addition to being highly critical of the government’s response to the humble address, the ISC criticised the “extraordinary” amount of government business taking place outside of official systems, such as on WhatsApp, and made what appeared to be a critique of the decision to grant Mandelson clearance against the advice of security officials.

“Lengthy WhatsApp conversations between senior officials and ministers appear now to be the format by which government policy is formulated,” it said. “Perhaps as a result, the lack of an audit trail – in terms of agendas, minutes and records of conversations, in the [Foreign Office] in particular – do not appear to be kept as a matter of practice. This is unacceptable in government.”

In a section headed “failure to adhere to security advice”, the ISC’s statement raised concern that the conclusions of security officials were not acted on. In an apparent reference to UKSV’s advice to the Foreign Office, it said: “Where advice is sought and obtained by those organisations whose job it is to ensure security, for that advice to be overruled to suit some other objective is not acceptable.”

It added: “Proper security concerns cannot be dismissed simply because they are inconvenient.”

Alex Burghart, the shadow chancellor of the duchy of Lancaster, said: “It is outrageous that Labour are trying to withhold documents about the Mandelson-Epstein affair from parliament.

“Throughout this process, Starmer and his ministers have sought to pull the wool over the public and parliament’s eyes. They only started releasing information because the Conservatives forced them to, and even now they are continuing the cover-up.”

The Cabinet Office has been approached for comment.

Oman has been caught in geopolitical crossfire after Iran said it was coordinating with Muscat over the future management of the strait of Hormuz, including Tehran’s plans – opposed by the US – for fees to be paid by commercial shipping to a new Iranian government agency.

The Omani exclave of Musandam lies to the south of the contested waterway, which normally carries a fifth of the world’s seaborne oil traffic but has been blockaded for 10 weeks since since the US-Israeli attack on Iran in February.

The US has said repeatedly there can be no permanent solution to the blockade that involves the payment of a toll to the Iran, and claims that Oman holds a similar view.

Speaking in India on Friday, the Iranian foreign minister, Abbas Araghchi, defined the strait of Hormuz as an exclusively Omani-Iranian waterway. “The strait is located in the territorial waters of Iran and Oman,” he said. “There is no international waters in between.”

Araghchi added that Iran was coordinating with Oman about the future management of the strait. Oman has so far been silent about Iran’s plans to charge a fee and to demand details on the nationality of all ships passing through the the waterway.

Western diplomats say Iranian proposals for the future permanent management of the strait are unlawful since they impose tolls on commercial shipping and would give Iran an arbitrary right to select the ships that are allowed passage, possibly based on the nationality of ownership. A requirement that every ship set up a rial account to pay for services would also probably fall foul of UN sanctions prohibiting money being sent to the Islamic Revolutionary Guard Corps (IRGC).

A rival plan based on the freedom of navigation being prepared by France and UK has also been put to Oman, and has the support of most Gulf states.

British officials including the Foreign Office’s political director, Lord Llewellyn, has been recently been in Muscat, as has the secretary general of the International Maritime Organization, Arsenio Dominguez.

The legal rights of coastal states to impose tolls lies at the heart of the deadlock on how to reopen the strait and whether Iran’s proposed regime, by restricting freedom of navigation, is illegal and sets a precedent for other similar waterways.

Iran became a signatory to the UN convention on the law of the sea (Unclos) in 1982, very soon after the 1979 revolution, but never ratified the treaty. This means that from Iran’s perspective it is not bound by the treaty’s transit passage rules that underpin freedom of navigation, but instead by customary international law, including a more restrictive right of innocent passage.

Iran claims that even if it is bound by Unclos, the enhanced right of transit passage to ships of nations is conditional and passage specifically can be restricted in the event of any threat or use of force against “sovereignty, territorial integrity or political independence of the coastal states”.

Tehran said at the outset of the conflict that the southern shore of strait including the United Arab Emirates was used by the the US to arm American bases to attack Iran.

Iran hopes the Persian Gulf Strait Authority, government agency it established on 5 May, will become profitable revenue-generating stream. A grey area is whether Iran can only charge fees in return for providing services to ships, or whether in reality it would be compulsory to use those services, so in effect turning the service fee into a toll.

The PGSA says ships now have to register by email with its office to receive routing information and permission to pass the strait.

Payment would be required in Iran’s national currency. The fee is being set at roughly a dollar a barrel.

Donald Trump at his summit in Beijing claimed that China – which imports almost 45 % of Iran’s oil production through the strait – agreed with the US that there could be no tolls and no restrictions. The US secretary of state, Marco Rubio, has also said China does not favour tolls.

The Chinese foreign ministry said it simply wanted the blockades to end and that the cause of the closure was the US-Israel war on Iran.

However, the IRGC briefed on Thursday that after talks with China’s ambassador to Iran a large group of Chinese oil tankers were being let through the strait by Tehran and that these ships had agreed to be subject to Iranian regime. The wording did not not reveal whether a fee was paid by China.

At the time the US imposed its blockade of Iranian ports, as a counter-measure to the Iran’s effective closure of the strait, Trump said: “No one who pays an illegal toll will have safe passage on the high seas.” That implied the US navy might feel entitled to block Chinese oil tankers if they paid a toll to Iran. However, it would be hard to gain evidence at the relevant moment whether a toll, or fee had been paid.

Virginia’s Democratic governor, Abigail Spanberger, vetoed a bill on Thursday that would have restored collective bargaining rights for 50,000 public sector workers in the state. Union leaders say the veto is a “betrayal” and “slap in the face” after the governor campaigned last year on promises to restore collective bargaining rights.

Though majorities in both chambers of Virginia’s general assembly passed legislation that would restore bargaining rights to most public sector workers, Spanberger introduced an amended version of the bill last month that was eventually rejected by the assembly.

According to an analysis from the Economic Policy Institute, Spanberger’s amended bill so heavily weakened the collective bargaining rights initially passed by the general assembly that it would “lock Virginia into an unstable, ineffective system in which collective bargaining would remain merely ‘optional’”.

The veto was praised by conservatives who claimed the bill would have brought on large tax increases.

Union leaders say the veto is an about-face from promises she made on the campaign trail. In February, a month after entering office, the governor attended a rally in support of the bill held by the Service Employees International Union (SEIU), according to the Virginia Mercury.

The SEIU leaders April Verrett, LaNoral Thomas and Jaime Contreras said in a joint statement said the veto was a “betrayal of Virginia’s workers who were promised change”.

“Collective bargaining is not a privilege – it is a right. Governor Spanberger looked workers in the eye, met with our members, affirmed her support, and made a promise. Today, she broke it,” they said.

Edward Kelly, president of the International Association of Fire Fighters, also said the veto “is a slap in the face to every worker who put their faith in her”. Of the state’s 11,000 firefighters, about 8,000 to 9,000 still do not have collective bargaining rights as their municipalities have not opted into having them.

“Firefighters keep their word every single day on the job. It’s a shame the governor can’t do the same,” Kelly said.

Lee Saunders, president of the American Federation of State, County and Municipal Employees (AFSCME), the largest union of public sector workers in the US with 1.4 million members, noted the history of “anti-worker extremists” in Virginia who have given the state the “reputation as one of the most anti-worker in the country”.

“Governor Spanberger campaigned on the promise to end this historic injustice. But she has broken that promise by vetoing legislation that would have finally granted most state and local workers the freedom to collectively bargain,” Saunders said.

The Virginia Public Sector Labor Coalition, a group of multiple major labor unions, echoed sentiments of betrayal and noted Glenn Youngkin, Spanberger’s Republican predecessor, vetoed similar legislation last year.

A spokesperson for Spanberger deferred comment to a press release and said the governor signed into law other legislation last month that expands paid family and medical leave, raises the minimum wage and helped cracks down on wage theft.

“I remain committed to continuing to work with the General Assembly, unions, localities and public servants across the Commonwealth to develop a public sector collective bargaining system that works for Virginia,” Spanberger said in a statement. “However, I believe additional amendments are needed to the enrolled bill currently before me.”

During the Jim Crow era, Virginia banned public sector collective bargaining in 1948 in response to a group of Black workers organizing a union at the University of Virginia hospital.

Before Virginia passed a law that permits local governments to enact their own collective bargaining system in 2021, the state was one of only three that have blanket bans on collective bargaining for public sector workers. Even after the law passed, collective bargaining for state government workers remains illegal.