The new chairman of Parliament’s Intelligence and Security Committee has condemned Downing Street’s attempt to impose its “preferred candidate” to lead the

committee.

Backbench MP for New Forest East Julian Lewis said he did not respond to a call to vote for former cabinet minister Chris Grayling as he considered it to be an “improper request”.

Mr Lewis was expelled from the parliamentary Conservative Party on Wednesday after securing the prestigious ISC chairmanship with the support of opposition members.

In a statement, he said that the 2013 Justice and Security Act explicitly removed the right of the prime minister to choose the ISC chairman and gave it to the committee members.

“It was only yesterday afternoon 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,” he said.

“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.”

A senior Government source said Mr Lewis had had the Conservative whip withdrawn because he had been “working with Labour and other opposition MPs for his own advantage”.

However, Mr Lewis said Downing Street had publicly declared it did not have a favoured candidate for the post, despite widespread reports of a whipping operation to get the Tories on the committee to vote for Mr Grayling.

“In recent days, the official No 10 spokesman explicitly denied that the Government was seeking to ‘parachute’ a preferred candidate in to the chair, stating that it was a matter for the senior parliamentarians on the committee to decide,” he said.

“It is therefore strange to have the whip removed for failing to vote for the Government’s preferred candidate.”

Mr Johnson’s choice of Mr Grayling to head the ISC – which oversees the work of the intelligence agencies MI5, MI6 and GCHQ – drew heavy criticism from across the political spectrum.

Unlike previous chairmen, the former transport secretary had little experience of security matters and was dubbed “failing Grayling” for a series of policy blunders during his time in government.

In contrast, Mr Lewis is a former chairman of the Commons Defence Committee, who has taken a close interest in defence and security issues throughout his time in Parliament.

In a further blow to the Prime Minister, Mr Lewis’s Conservative association declared its “full support” for the

MP.