Sir Keir Starmer has been warned that the government must not withhold any information relating to the appointment of Peter Mandelson as ambassador the US – or he could face a contempt motion.
Concerns have been raised over whether ministers will comply with a vote to release all the papers relating to the appointment, after the Intelligence and Security Committee (ISC) – which is overseeing the release of the documents – warned that the government is redacting more information than was initially agreed.
A fresh tranche of papers is expected to be published next week following a meeting of the ISC, which has already resolved to tell the government it will have to indicate where it has redacted material without the permission of the committee.
The Tories have confirmed they will table a motion holding ministers in contempt of parliament if the government fails to comply with the humble address on the publication of all material relating to the appointment, which is likely to target individual ministers responsible, including the prime minister.
A number of Labour MPs have already confirmed that they will support the motion, which would then trigger an inquiry by the Commons Privileges Committee.
Shadow foreign secretary Priti Patel told The Independent: “Labour ministers are up to their necks in this scandalous cover up of the Mandelson-Epstein files.
“The Conservatives pushed in parliament for full transparency, backing the ISC to have the final say on how this information was put out. Instead we have Labour ministers walking all over due process and ignoring what was unanimously decided by Parliament.
“Labour are lying to the country. Should they defy parliament’s will by refusing to release key files – a clear example of contempt – we will use every available tool to force them to come clean with MPs and the public.”
One of the Labour MPs willing to back a contempt motion, Kim Johnson, told The Independent: “I think colleagues would be inclined to support this, they would want to distance themselves from the corruption and sleaze.”
Another Labour MP said: “Starmer he has no authority and anything he now does that undermines us (Labour) further will have limited tolerance.”
But the MP noted: “It would be better if it came from the Lib Dems as it would be harder for Labour MPs to be associated with Tory games.”
The humble address motion brought by the Tories allowed for only the Intelligence and Security Committee (ISC) to decide whether information needed to be redacted on national security grounds.
A source told The Independent: “The humble address is very specific it only gives the committee the power to redact not the government. So if the government goes ahead and redacts things it will not be complying with the humble address and that will open a whole can of worms.”
The Tories have already noted that a precedent was set during the Brexit negotiations when another humble address forced the government to reveal the papers linked to the exiting the EU talks.
A source who worked in Downing Street at the time said: “The government blinked on that one once a contempt vote was threatened.”
It is understood that the issue has been informally raised with the Speaker Sir Lindsay Hoyle over what might happen if the will of the Commons is ignored.
The Commons press office has said that Sir Lindsay will not comment on any discussions or hypotheticals, but senior Labour figures could find themselves at odds with the government on the issue.
Ministers only caved in and agreed to the humble address after former deputy prime minister Angela Rayner intervened in the debate to force the government to back down over attempts to limit publication.
Independent MP Karl Turner, who has been suspended from the Labour Party after criticising judicial changes, has revealed that he has discussed the potential contempt of parliament vote with veteran Tory MP Sir David Davis.
He said: “There are only maybe 35 to 45 Labour backbenchers that would have the bottle to support a contempt motion. The bigger concern for the government is abstentions. Far too many are just simply finding excuses not to be there for important votes.”
He went on: “The PM doesn’t have any authority left at all. The last motion [for a privileges committee inquiry] was defeated of course but MPs were livid that we’d been forced to get there.
“Far too many abstained. And those that didn’t made it abundantly clear that they would not allow to have targets placed upon their backs for the sake of saving Starmer when we all know that he’s dead.”
A Downing Street spokesperson said: “As we have repeatedly said, we are committed to complying with the humble address in full.”
