The new chairman of the UK intelligence watchdog has accused Boris Johnson of behaving in an “improper” way by trying to get another candidate elected.
Julian Lewis was chosen to head the Intelligence and Security Committee, despite Boris Johnson urging Tory members to vote for Chris Grayling.
After running against Mr Grayling and winning, Mr Lewis was expelled from the Conservative Parliamentary Party.
He said he had not given an “undertaking” to back anyone else.
The ISC has also unanimously agreed to publish its long-awaited report into alleged Russian meddling in UK elections before Parliament’s summer recess.
Concerns were raised after nominations to the parliamentary committee – five out of nine of them Conservatives – were announced by the government last week.
Critics said its impartiality could be undermined if ministers then asked the Tory members to back Mr Grayling, a former Conservative cabinet minister, for chairman.
But it took Westminster by surprise when Mr Lewis ran and won with the support of three Labour members and one SNP member, leading to him losing the party whip.
A senior government source told the BBC that Mr Lewis had “been told by the chief whip that it is because he worked with Labour and other opposition MPs for his own advantage”.
But in a statement, Mr Lewis, MP for New Forest East, said the 2013 Justice and Security Act had “explicitly removed the right of the prime minister to choose the ISC chairman and gave it to the committee members”.
He added: “It was only yesterday afternoon [Thursday] that I received a text asking me to confirm that I would be voting for the prime minister’s preferred candidate for the ISC chair.
“I did not reply as I considered it an improper request. At no earlier stage did I give any undertaking to vote for any particular candidate.”
Mr Lewis also said the government had denied wanting to “parachute” a preferred candidate in to the chair, adding:”It is therefore strange to have the whip removed for failing to vote for the government’s preferred candidate.”
Asked whether the decision to expel Mr Lewis from the Conservative parliamentary party had been the right one, Business Secretary Alok Sharma said it was “a matter for the whips” and the committee could “now move forward with its work”.
But Sir Malcolm Rifkind – a former foreign secretary who chaired the committee between 2010 and 2015 – told BBC Radio 4’s Today programme it was “ridiculous” to consider people voting for Mr Lewis as “improper”, and that the Tory MP was the “most qualified” for the job.
Another former chairman of the committee, ex-Tory MP Dominic Grieve – who had the whip removed over his views on Brexit – told the BBC’s Newsnight that No 10 should not have tried to “manipulate this process”.
For Labour, shadow foreign secretary Lisa Nandy tweeted that it had been a “completely self-defeating act that bears the hallmark of a government so arrogant it really believes it is above scrutiny”.
The ISC was disbanded in November last year ahead of the general election and has not sat since – its longest hiatus since it was established in the mid-1990s.
One of the first jobs of the newly formed committee will be to publish its report on alleged Russian interference in UK politics – held up by the election and then the delay in setting up the committee, despite being given clearance for publication by No 10.
The report includes evidence from UK intelligence services concerning Russian attempts to influence the outcomes of the 2016 EU referendum and 2017 general election.
The delay in publication has led to speculation the report contains details embarrassing for the Conservatives.
But Leader of the House Jacob Rees-Mogg said the hold-up was due to a number of committee members leaving Parliament and the need “to make sure that the right people with the right level of experience and responsibility could be appointed”.