The centrist Remainer outsider said MPs would oppose Mr Johnson and ‘bring him down’ if he attempted to side-step attempts to block leaving without a deal.
Mr Stewart made the astonishing remarks to Sky News minutes after former foreign secretary romped away from the rest of the first in the first round of the ballot.
Mr Johnson has so far not ruled out proroguing Parliament – ending the current session – to prevent MPs from trying to block a No Deal Brexit or topple his government if elected Conservative leader.
After surprising Westminster and making it to the second round the International Development Secretary said: ‘That is an unconstitutional, improper, really disturbing suggestion – that you try to get something through by locking the doors of Parliament.
‘Answer us. I’ve been asking Boris for a week. Tell people because we want to know what kind of leader or prime minister you would want to be.
‘But he won’t be able to. I guarantee if he were to try, I, and every other MP will sit across the road in Methodist Central Hall and we will hold our own session of Parliament and we will bring him down.
‘Because you do not, ever, lock the doors on Parliament in this country, or indeed in any country with any respect in the world.’
The former foreign secretary topped the secret ballot with backing from 114 MPs – ahead of Jeremy Hunt in second with 43
Mr Johnson took a massive towards Downing Street today as he stormed home in the opening round of the Tory leadership battle.
The former foreign secretary topped the secret ballot with backing from 114 MPs – ahead of Jeremy Hunt in second with 43.
The higher-than-expected score for Mr Johnson – which drew gasps in the Committee Room 14 when it was announced – means he is almost guaranteed to make the final run-off among Tory members.
Bookmakers immediately slashed the odds on Mr Johnson being the next PM from 4/9 to 1/5 after today’s announcement read out by Cheryl Gillan
Talking of attempts to shut down Parliament, Mr Stewart said: ‘That’s what Charles I did – that led to very disturbing things in this country’
Bookmakers immediately slashed the odds on Mr Johnson being the next PM from 4/9 to 1/5.
Environment Secretary Michael Gove was third on 37, after his campaign was badly damaged by his cocaine admission over the weekend. Former Brexit Secretary Dominic Raab received 26 votes, Sajid Javid 23 and Matt Hancock 20.
And Mr Stewart just squeezed over the threshold of 17 votes needed from the total of 313 to continue to the next round, with 19.
He also drew a comparison with Charles I’s actions which precipitated the English Civil War in the 17th century, saying: ‘Somebody who tried to subvert our constitution, our liberties, our Parliament, who dared to stand as Prime Minister and claim they could lock the doors on Parliament, would not deserve to be Prime Minister and we would bring him down.
If he tried to do it – he would be doing it knowing that Parliament was almost entirely against the central plank of this policy. He would try to stop us by stopping us being able to sit.
‘That’s what Charles I did – that led to very disturbing things in this country.
I’m sure he doesn’t mean it – I’m sure like his taxation policy he hasn’t thought it through. We need a serious prime minister for a serious country.’
It’s ‘unfair’ to involve the Queen in politics by asking her to shut down Parliament, says minister
The Queen should be ‘kept out of politics’ and it would be ‘unfair’ to ask her to temporarily shut down Parliament, according to a Cabinet minister.
Commons Leader Mel Stride said he and his Conservative colleagues did not want to involve the monarch in political matters, before adding that he believes MPs are united in trying to secure a Brexit deal.
His remarks came after shadow Commons leader Valerie Vaz raised Labour’s concerns over Tory leadership candidates suggesting they could prorogue Parliament to ensure the UK leaves the EU without an agreement on October 31.
She also unsuccessfully pushed Mr Stride to offer dates for the summer recess given the ongoing uncertainty over Parliament’s role in the coming weeks on Brexit.
Mr Stride told MPs: ‘(Ms Vaz) raised the issue of proroguing Parliament as, I’m sort of paraphrasing her comments, a device to perhaps ensure a no-deal situation in the absence of Parliament sitting.
‘That is not the Government’s policy at all and it is certainly the feeling on this side of the House that Her Majesty the Queen should be kept out of politics.
‘It’d be unfair to draw her into a political situation in that form.’