Boris Johnson's resignation letter and May's reply in full

LONDON ― U.K. Foreign Secretary Boris Johnson on Monday was the latest cabinet minister to resign over Brexit negotiations, placing Prime Minister Theresa May's grip on power in doubt just days before U.S. President Donald Trump is set to visit Britain.

British Prime Minister Theresa May dug in her heels today after the resignation of two top government ministers over Brexit negotiations whipped up a storm that threatened to topple her fragile minority government.

May, the leader of the Conservative party, believed she had secured a hard-won agreement with her deeply divided cabinet of ministers on Friday to keep the closest possible trading ties with the EU. Jacob Rees-Mogg, who leads a bloc of Brexit-supporting Conservative MPs in Parliament, urged May to give up on the plan.

But Mrs May hit back in her icy letter accepting his resignation - effectively accusing him of signing up to the Chequers plan before walking away.

Mr Johnson does not pull any punches, saying Brexit "should be about opportunity and hope" and a "chance to do things differently", but "that dream is dying, suffocated by needless self-doubt".

Both Brexiteers and Remainers might consider voting the deal down during the meaningful vote, with each side convinced that such an act would or wouldn't trigger a no-deal Brexit, respectively.

The U.K.is slated to exit the European Union on March 29 of 2019, kicking off an implementation period that will run through the end of 2020.

Johnson, who assumed his position as foreign secretary in July of 2016, previously admonished then-GOP presidential nominee Donald Trump for his criticism of North Atlantic Treaty Organisation.

"I like Theresa May, I think she's a good prime minister", Davis said.

In recent weeks, junior ministers Phillip Lee and Greg Hands have also resigned in order to vote against government - the former over Brexit, the latter over Heathrow.

If Davis's resignation rattled May, Johnson's shook the foundations of her government. In her statement to members of Parliament, May acknowledged the splits in her government, saying of the ministers who quit: "We do not agree about the best way of delivering our shared commitment to honoring the result of the referendum".

May said the plan would deliver frictionless trade with Europe and was the "only way to avoid a hard border" between the U.K.'s Northern Ireland and European Union member Ireland.

Mr Johnson said Britain was destined for a "semi Brexit" if the blueprint agreed by the Cabinet at Chequers on Friday is delivered.

Labour leader Jeremy Corbyn said Mr Johnson and Mr Davis had abandoned a "sinking ship", shattering the "illusion of unity" initially surrounding the Chequers plan. As I said then, the government now has a song to sing. The UK government is in turmoil, but that has been the case for more than two years. Many Tory Brexiteers have criticized this plan as a "soft Brexit" or "Brexit in name only". "In my view the inevitable effect of the proposed policies will be to make the supposed control by Parliament illusory rather than real". May appointed staunchly pro-Brexit lawmaker Dominic Raab as the country's new Brexit secretary. But even that now seems to have been taken off the table, and there is in fact no easy United Kingdom right of initiative.