Dwyfor Meirionnydd MP Liz Saville Roberts has told colleagues “to be ready to impeach” Prime Minister Boris Johnson.

The leader of Plaid Cymru in Westminster, Mrs Saville Roberts warned this week that impeachment may be necessary if Mr Johnson ignores the newly passed legislation requiring the Prime Minister to request an extension to avoid a ‘no deal’ Brexit.

It has emerged that Mr Johnson supported the last attempt to impeach a Prime Minister in 2004, co-signing the motion tabled by current Plaid Cymru leader and then-MP Adam Price seeking to impeach Tony Blair over the Iraq war.

The Prime Minister also wrote a column for The Telegraph at the time in which he outlined his support for Mr Price’s attempt to impeach Mr Blair and the process itself.

The process would see the House of Commons first vote on an impeachment motion, which, if passed, could lead to prosecution and trial.

Historically trials have taken place in Westminster Hall, on the Parliamentary estate.

Opposition party leaders have already agreed that Parliament should be sitting – and no General Election called – until Mr Johnson secures the extension as required by legislation.

Impeachment would be a process by which Parliament could hold Mr Johnson to account if he failed to comply with the law after the European Council on 17 and 18 October, as he has threatened.  

Although a number of ministers up until the 19th century have been impeached, no Prime Minister has ever been successfully impeached.

Mrs Saville Roberts said: “Boris Johnson has already driven a bulldozer through the constitution, so no longer are ideas like impeachment farfetched.

“I will tell other opposition party leaders: we need to be ready to impeach Boris Johnson if he breaks the law.

“We cannot play the Prime Minister at his own cynical game. We need to be ready to fight fire with water, outsmart the smartest, think the unthinkable.

“Impeachment was a process backed by Boris Johnson not so long ago. A man sacked for serially lying backed the impeachment of Blair for the same reason – lying. If the Prime Minister becomes a law-breaker, we have an even stronger case for impeachment than the very cause he advocated back in 2004.

“No PM would want to play fast and loose with views he held on such matters in the past.

“The future of our communities are at stake and I will not let him get away with running them into the ground thanks to a plummy accent and a memorable haircut.

“They have brought a campaigner to a constitutional fight, when they should have brought a lawyer.

“No one is above the law, Boris Johnson shouldn’t risk finding that out the hard way.”