Boris Johnson labelled a 'preacher of division' by Lib Dem leadership hopeful Ed Davey

Liberal Democrat leadership hopeful Sir Ed Davey has branded Boris Johnson a "preacher of division" as he launched his bid to succeed Sir Vince Cable.

Sir Ed lumped Mr Johnson in with right-wing figures like Nigel Farage and Italy's deputy prime minister Matteo Salvini, and drew a direct comparison between the rise of their populist politics and the fascism of the 1930s.

He ruled out the possibility of coalition with a Johnson-led Tory party or Labour under Jeremy Corbyn in a hung parliament, saying the prospect of either was stomach-turning.

The Lib Dem home affairs spokesman is the first contender to throw his hat into the ring to replace Cable, who announced last week he will step down on July 23. He is expected to face stiff competition from current deputy leader and bookies' favourite Jo Swinson.

Launching his campaign in London, Sir Ed vowed to fight both Brexit and illiberal forces in modern politics.

"A decade after the 1920s recession we saw the rise of national populism - fascism. Fascists riding to power because good people underestimated them and their lies and demonisations," he said.

"Ten years after our great financial crash, we are seeing the same. The preachers of division, the Farages, the Salvinis, the Johnsons.

"I do not underestimate these dangerous people."

Asked whether he could contemplate a pact of any kind with either Mr Johnson or Mr Corbyn in a hung parliament, he said: "I think people's stomachs are turning. The idea that we have anything in common with Boris Johnson or frankly the Tory Party when they are promoting this no-deal Brexit? Just no way.

"And then Jeremy Corbyn? I don't trust him on Brexit - his own party don't. And I don't trust him on the economy either.

"We are not going into coalition with these people. If you vote Liberal Democrat you will get more Liberal Democrat MPs... you won't be getting a coalition with Tories or Labour."

He declined to say whether Lib Dems would facilitate a minority Johnson or Corbyn administration by voting through their Queen's Speech, saying: "I'm here to make sure Liberal Democrats are writing that Queen's Speech."

Unveiling a platform focused on stopping Brexit, "decarbonising capitalism", promoting green jobs and improving education, Sir Ed said success at local and European elections showed Lib Dems were "back in the game".

He revealed he was seeking to use a parliamentary "humble address” to the Queen to ensure that MPs are able to revoke Article 50 to stop a no-deal Brexit by default in October.

He was scornful of Mr Corbyn's gradual movement towards support for a Final Say referendum, saying that the Labour leader's comments on a public vote during his visit to Dublin reminded him of Irish writer Samuel Beckett's most famous play.

"It's been like waiting for Godot," he said. "But remember, Godot never turned up."

Sir Ed said his message to Change UK MPs seeking closer co-operation was: "Come and join us. Come and join the biggest Remain party in the UK."

He declined to say whether there were any Change UK figures he would not welcome into the party because of their previous disobliging comments about the Lib Dems.

"I think we should be open-minded and generous and forgiving," he said. "People are entitled to make mistakes and if they sign up to liberal democracy and sign up to helping us stop Brexit, they are welcome to join our party."