Government whip Gareth Johnson quits ahead of Commons vote on Theresa May's Brexit deal

A Tory MP charged with quelling dissent in the party has quit the Government on the eve of the crucial Commons vote on Theresa May’s Brexit deal, after he branded it “detrimental” to the country.

Gareth Johnson quit as assistant government whip after just two months in the job so that he could join dozens of Tory MPs who have pledged to vote down the agreement.

Johnson, a former parliamentary aide to former Brexit Secretaries David Davis and Dominic Raab, said he could no longer “reconcile” his role of trying to persuade MPs to back the deal when he “cannot, in all conscience, support the Government’s position”.

“I have prided myself on being a loyal Member of Parliament and I was very grateful to be given the opportunity by you last year to serve in the Government Whips’ Office,” he wrote in his resignation letter to the Prime Minister.

"I am also proud of the many achievements of this Government but I believe it would be disrespectful to the referendum results of this agreement were to be implemented.

“I have therefore decoded the time has come to place my loyalty to my country above my loyalty to the Government."

He added that he had been “hopeful” that changes could be agreed with EU chiefs since Mrs May postponed the initial planned Commons vote in December but added that it was clear “that no significant change will be made”.

And he backed claimd that the deal threatened the union between Great Britain and Northern Ireland.

“Unfortunately this agreement prevents us taking back control and instead could leave us perpetually constrained by the European Union,” he said.

“Like you, I am not only a Conservative but I am also a committed Unionist and I cannot accept the additional regulatory compliance required of Northern Ireland that would set it apart from the rest of the United Kingdom.

Former Brexit minister and vice-chair of the European Research Group, Steve Baker, tweeted that Mr Johnson's move to quit the frontbench was "the right thing to do" and that he was a “hero” for it.

It is thought that other members of the Government could also quit ahead of tomorrow night's vote.

The intervention came hours after EU heads Jean-Claude Juncker and Donald Tusk sought to give assurances to MPs that the Irish backstop cannot be permanent.

The PM admitted however that their pledges, which include assurances that the measure will be “temporary” did not “go as far as some MPs would like”, given it could not promise an end date or that UK could leave it unilaterally.

Nigel Dodds, the Westminster leader of the DUP, who Mrs May relies on to prop up her minority government, said the letter “bolsters” the Northern Ireland unionist party’s opposition.

“Despite a letter of supposed reassurance from the European Union, there are no “legally binding assurances” as the Prime Minister talked about in December. In fact, there is nothing new. Nothing has changed," he said.