London (AFP) - Britain's ruling Conservative party was locked in a new row over Brexit Sunday after Boris Johnson said the government's strategy put the country in a "suicide vest", with Brussels holding the detonator.
The former foreign minister's remarks ramp up his criticism of Prime Minister Theresa May's approach to leaving the European Union, amid speculation he is positioning to replace her.
Writing in the Mail on Sunday newspaper, Johnson repeated that May's plan to follow EU rules on trade in goods after Brexit -- a plan over which he quit his job in protest in July -- were a "humiliation".
And he condemned her vow to do whatever it takes to avoid border checks in Ireland, saying it was "insanity" and left Britain open to "perpetual political blackmail".
"We have wrapped a suicide vest around the British constitution -- and handed the detonator to (EU Brexit negotiator) Michel Barnier," he wrote.
"We have given him a jemmy (crowbar) with which Brussels can choose -- at any time -- to crack apart the union between Great Britain and Northern Ireland."
The EU has suggested that if no other way was found to avoid physical border checks between Ireland and the British province of Northern Ireland, then the latter should stay aligned with the bloc's trade rules.
May has rejected this as unacceptable, but the two sides are deadlocked as time runs out to agree a divorce deal before Brexit in March next year.
Johnson's inflammatory language drew outrage from colleagues, with junior foreign minister Alan Duncan saying it was "disgusting" to compare May's view to that of a suicide bomber.
"I'm sorry, but this is the political end of Boris Johnson. If it isn't now, I will make sure it is later. #neverfittogovern," he tweeted.
Johnson's successor, Foreign Secretary Jeremy Hunt, wrote in a rival article in the Mail that "nobody else has a detailed plan" for Brexit, adding: "This is the moment to back the prime minister."
Some commentators suggested Johnson's remarks were intended as a diversion from speculation over his private life, after he announced this week that he was divorcing his wife of 25 years.
Sunday's newspapers were filled with lurid details about Johnson's alleged infidelity in the past.
They were said to be from a dossier compiled by May's office in 2016, when she was competing with Johnson for the Conservative leadership.
Downing Street denied re-releasing the details to discredit him now.