With Parliament thrust into crisis, the need for constitutional expertise is paramount.

Step forward the celebrity Remainer luvvies, whose howls of outrage are more petulant than ever . . .

PHILIP PULLMAN, author: 'The Prime Minister has finally come out as a dictator. I've had enough of being outraged. We must get rid of him and his loathsome gang as soon and as finally as possible. When I hear the name Boris Johnson, for some reason the words 'rope' and 'nearest lamp-post' come to mind as well.

[Pullman was later forced to clarify: 'Just to make it perfectly clear: I wouldn't kill the Prime Minister, and I don't want anyone else to. But I don't apologise for the anger I feel; only for its intemperate expression.']

JAMES O'BRIEN, LBC radio presenter: 'What's happened so far happened because the people with the strongest opinions about EU membership turned out to be the ones with the weakest understanding of it. What happens next depends on the same people's willingness to admit to career-long ignorance. I'm not optimistic.'

James O'Brien, a radio presenter for LBC, and singer Paloma Faith are among the celebrity bandwagon criticising Boris Johnson's Brexit move

PALOMA FAITH, singer: 'Please sign this petition against this ridiculous UK dictatorship.'

ED MILIBAND, former Labour leader: 'Suspending Parliament to prevent the expression of the will of elected representatives is what autocrats and dictators do. This attempted coup against our democracy to impose a No Deal Brexit cannot be allowed to stand.'

FINANCIAL TIMES editorial: 'History has shown that charlatans, demagogues and would-be dictators have little time for representative government.'

Piers Morgan poked fun at Hugh Grant's piety after the actor said he was 'revolted' by Boris Johnson

GINA MILLER, anti-Brexit campaigner: 'These actions are more akin to dictatorship than democracy and as such their legality must be tested in the courts.'

PAUL MASON, former economics editor of BBC2's Newsnight: 'To stop Farage and Johnson destroying our democracy we need not just an alliance in Parliament: we need to get on the streets . . . and if it comes to an election — a one-time tactical voting pact for the progressive majority.'

LORD (BOB) KERSLAKE, former head of the Civil Service: 'We are reaching the point where the Civil Service must consider putting its stewardship of the country ahead of service to the government of the day.'

JOHN SIMPSON, BBC world affairs editor: 'Just back from the WiFi-free South African wilderness to find a full-scale constitutional crisis under way. Downing Street assured the BBC on Sunday that it was entirely false to claim Parliament would be prorogued. Is truth just going out of the window?'

Anti-Brexit campaigner Gina Miller has vowed to fight Boris Johnson's prorogation in the courts while Stephen Fry labelled it a 'coup d'état'

ALASTAIR CAMPBELL, Tony Blair's No 10 spin doctor: 'The campaign Take Back Control was meant to be about parliamentary sovereignty, we've had an Old Etonian Prime Minister tell an Old Etonian Cabinet minister to go up and see the Queen in a Scottish castle to shut down Parliament.'

POLLY TOYNBEE, Guardian columnist: 'A constitution that relied on gentlemanly governments' willingness to bow to Parliament has evaporated, blown away now it's led by a man who doesn't give a damn for parliamentary sovereignty: taking back control is for him alone. He is ready to destroy anything that threatens his ambition.'

A.C. GRAYLING, philosopher: 'The people convicted of crimes in the 2016 Leave campaign are now on Downing Street committing constitutional crimes. As former Civil Service head Lord Kerslake in effect suggests, the Civil Service should go on strike. A general strike might be necessary to #BlockTheCoup.'

Paul Mason, former economics editor of BBC2's Newsnight, and John Simpson, BBC world affairs editor, joined in on the outrage

GARY LINEKER, ex-footballer and TV presenter: 'The Government's argument that they're doing this for democracy is remarkably undemocratic.'

BILLY BRAGG, singer: 'More proof that Johnson will go to any lengths to avoid debating his Brexit plans because to do so would merely highlight his vacuity. The last person who tried to suspend parliament was Charles I and we know what happened to him.'

DAVID WALLIAMS, actor: 'The only thing necessary for the triumph of evil is for good men to do nothing' — Edmund Burke.

BBC top earner Gary Linekar said the government's actions are 'remarkably undemocratic'

GUY VERHOFSTADT, EU Brexit coordinator: 'Taking Back Control has never looked so sinister. As a fellow parliamentarian, my solidarity with those fighting for their voices to be heard. Suppressing debate on profound choices is unlikely to help deliver a stable future EU-UK relationship.'

ANDREW ADONIS, Labour peer: 'Brexit is a revolution weakening and undermining our core national institutions one by one. Yesterday it was the monarchy, commandeered by Johnson to undermine Parliament. This will continue until Brexit is stopped.'

ALAN RUSBRIDGER, former Guardian editor: 'This is a full scale revolution by Dominic Cummings [the PM's senior adviser], who literally holds Parliament in contempt.'

GAVIN ESLER, former BBC journalist: 'Either we have parliamentary sovereignty or we have dictatorship by a Prime Minister not elected by the British people.'

CHARLIE BROOKER, author and TV presenter: 'Liars. Vandals.'

Dragons' Den star Deborah Meaden and comedy writer Armando Iannucci vented their frustrations

DEBORAH MEADEN, Dragons' Den 'investor' and businesswoman: 'So they suspend Parliament and then shut the doors on communication. People, this is a coup.'

RICHARD DAWKINS, biologist: 'Whatever else 'Take back control' meant, it surely did not mean a coup d'état to wrest control from Parliament and hand it over to a dictator.'

ARMANDO IANNUCCI, creator of TV's In The Thick Of It: 'In this exceptional time, protests should be more than about venting frustration; they need to be effective. Those who've undermined our democracy won't take any notice of protests outside Parliament. They will, though, if they were outside Buckingham Palace.'