Ms Rudd, a well-known Remainer, blamed Mr Johnson’s “purge” of the party which has seen him remove the whip from 21 MPs and a “failure” to pursue a deal with the EU in a strongly worded resignation letter in which she accused him of “political vandalism”. She wrote: “This has been a difficult decision. “I joined your cabinet in good faith: accepting that ‘No Deal’ had to be on the table, because it was the means by which we would have the best chance of achieving a new deal to leave on October 31.
Amber Rudd has resigned from Boris Johnson’s cabinet
“However I no longer believe leaving with a deal is the government’s main objective.
“The Government is expending a lot of energy to prepare for ‘No Deal’ but I have not see the same level of intensity go into our talks with the European Union who have asked us to present alternative arrangements to the Irish backstop.”
Ms Rudd continued: “I must also address the assault on decency and democracy that took place last week when you sacked 2 talented, loyal One Nation Conservatives.
“This short sighted culling of my colleagues has stripped the party of broad-minded and dedicated Conservative MPs.
Amber Rudd has resigned from Boris Johnson’s cabinet – and the Tory Party
I cannot support this act of political vandalism
“I cannot support this act of political vandalism.
“Therefore, it is with regret that I am also surrendering the Conservative whip.”
She has also suggested there is “no evidence” Mr Johnson was trying to get a new Brexit deal with the European Union. She told The Sunday Times she was considering fighting the next election as an “independent Conservative” in seat other than her current Hastings and Rye constituency.
Boris Johnson only appointed his cabinet on July 23
In a video statement carried on the newspaper’s website, she said: “I have been surprised, unfortunately, by the lack of work and preparation that is going into getting a deal with the European Union.
“I knew and I accepted that the prime minister should be able to leave no-deal on the table, but what I had expected to see was a huge government-centred effort to get a deal, and at the moment there is a lot of work going on to no-deal and not enough going into getting a deal.”
Ms Rudd added: “On top of that I’ve seen 21 of my colleagues, good, strong conservative MPs with true moderate, progressive values, excluded from the party, indicating that the Conservative Party that is such a force for good in this country no longer has a place for people who have different views on the EU.
An excerpt from Ms Rudd’s letter of resignation
“I can’t stand for that, so, as well as resigning from cabinet, I have decided to surrender the Conservative whip and to join them.”
Rudd says she is planning to join forces with the 21 other rebels to work to ensure Britain does not leave with no deal.
“I will be considering my position – whether I will stand as an independent Conservative should there be an election coming up.”
Amber Rudd has quit Boris Johnson’s cabinet
Former Home Secretary Ms Rudd, one of the most prominent Remainers in the Parliamentary Conservative Party, hinted at a possible challenge in April in the last few weeks of Theresa May’s tenure.
She told Radio 5’s Emma Barnett: “I think what I have said is I am not planning to run.
“I have kept the door slightly ajar but I am not committed to it at the moment.”
Eyebrows were raised therefore after she subsequently backed Mr Johnson and accepted her old job back in his cabinet.
Ms Rudd has represented her constituency since 2010 and has one of the smallest majorities in the country, with only 346 votes separating her from her Labour rival in 2017.
Former Conservative MP and minister Nick Boles – who quit the party in April after his soft Brexit plan failed – tweeted: “Everyone has a point beyond which they cannot be pushed.
“Amber Rudd has reached hers.
“How much more of the party he inherited will Johnson destroy before he has second thoughts or is stopped by his Cabinet colleagues?”
Labour Party chairman Ian Lavery MP commented: “The Prime Minister has run out of authority in record time and his Brexit plan has been exposed as a sham.
“No one trusts Boris Johnson. Not his Cabinet, not his MPs, not even his own brother.
“After nine years of austerity, we need a Labour government that will invest in our communities and public services.”