Boris Johnson and Jeremy Corbyn will trade blows as they kick off their parties’ election campaigns by launching blistering attacks on each other.

Mr Johnson will accuse Mr Corbyn of “incessant indecision”, while the Labour leader will use his first speech of the campaign to brand his rival’s party the “born-to-rule Conservatives”.

Mr Corbyn is also expected to attack businessmen including Sports Direct founder Mike Ashley and media magnate Rupert Murdoch as he promises to overturn a “corrupt system”.

The political parties are rapidly ramping up their campaigning after MPs voted for a general election on 12 December – the third in the UK in just four years.

While parliament is not expected to be disbanded until early next week, the leaders are already in full campaign mode.

Best pictures from Final Say Brexit march Show all 76 1 /76 Best pictures from Final Say Brexit march Best pictures from Final Say Brexit march Crowds march through central London Getty Best pictures from Final Say Brexit march People's Vote Final say march - 19 October 2019 Angela Christofilou Angela Christofilou/The Independent Best pictures from Final Say Brexit march Protesters gather in Parliament Square Led By Donkeys Best pictures from Final Say Brexit march Mayor of London Sadiq Khan joins protesters PA Best pictures from Final Say Brexit march People's Vote Final say march - 19 October 2019 Angela Christofilou Angela Christofilou/The Independent Best pictures from Final Say Brexit march People's Vote Final say march - 19 October 2019 Angela Christofilou Angela Christofilou/The Independent Best pictures from Final Say Brexit march People's Vote Final say march - 19 October 2019 Angela Christofilou Angela Christofilou/The Independent Best pictures from Final Say Brexit march People's Vote Final say march - 19 October 2019 Angela Christofilou Angela Christofilou/The Independent Best pictures from Final Say Brexit march Anti-Brexit protesters fill Parliament Square in London PA Best pictures from Final Say Brexit march People's Vote Final say march - 19 October 2019 Angela Christofilou Angela Christofilou/The Independent Best pictures from Final Say Brexit march People's Vote Final say march - 19 October 2019 Angela Christofilou Angela Christofilou/The Independent Best pictures from Final Say Brexit march People's Vote Final say march - 19 October 2019 Angela Christofilou Angela Christofilou/The Independent Best pictures from Final Say Brexit march People's Vote Final say march - 19 October 2019 Angela Christofilou Angela Christofilou/The Independent Best pictures from Final Say Brexit march People's Vote Final say march - 19 October 2019 Angela Christofilou Angela Christofilou/The Independent Best pictures from Final Say Brexit march People's Vote Final say march - 19 October 2019 Angela Christofilou Angela Christofilou/The Independent Best pictures from Final Say Brexit march People's Vote Final say march - 19 October 2019 Angela Christofilou Angela Christofilou/The Independent Best pictures from Final Say Brexit march People's Vote Final say march - 19 October 2019 Angela Christofilou Angela Christofilou/The Independent Best pictures from Final Say Brexit march People's Vote Final say march - 19 October 2019 Angela Christofilou Angela Christofilou/The Independent Best pictures from Final Say Brexit march People's Vote Final say march - 19 October 2019 Angela Christofilou Angela Christofilou/The Independent Best pictures from Final Say Brexit march A demonstrator marches EPA Best pictures from Final Say Brexit march People's Vote Final say march - 19 October 2019 Angela Christofilou Angela Christofilou/The Independent Best pictures from Final Say Brexit march People's Vote Final say march - 19 October 2019 Angela Christofilou Angela Christofilou/The Independent Best pictures from Final Say Brexit march People's Vote Final say march - 19 October 2019 Angela Christofilou Angela Christofilou/The Independent Best pictures from Final Say Brexit march Protesters push a float depicting Dominic Cummings using Boris Johnson as a puppet during the Final Say Brexit march in London PA Best pictures from Final Say Brexit march EU supporters react after the result of the vote on the deal delay was announced at the House of Commons REUTERS Best pictures from Final Say Brexit march A demonstrator carries his dog draped in EU flag AP Best pictures from Final Say Brexit march Thousands of people taking part in a People's Vote march AFP/Getty Best pictures from Final Say Brexit march Protesters use their flags to shelter from the rain Getty Images Best pictures from Final Say Brexit march Protesters march towards Parliament Square Getty Images Best pictures from Final Say Brexit march Anti-Brexit demonstrators carry placards and EU flags AP Best pictures from Final Say Brexit march Sir Oliver Letwin MP in Parliament Square, London, during an an anti-Brexit, Let Us Be Heard rally, after it was announced that the Letwin amendment, which seeks to avoid a no-deal Brexit on October 31, has been accepted PA Best pictures from Final Say Brexit march Thousands of people taking part in a People's Vote march UK BROADCASTERS POOL/AFP via Get Best pictures from Final Say Brexit march A protester with "Bollocks to Brexit" stickers on his head Getty Images Best pictures from Final Say Brexit march Demonstrators march EPA Best pictures from Final Say Brexit march Britain's main opposition Labour Party shadow Secretary of State for Exiting the EU Keir Starmer, shadow Home Secretary Dianne Abbott, shadow Chancellor of the Exchequer John McDonnell, shadow Foreign Secretary Emily Thornberry speaks on stage in Parliament Square AFP via Getty Images Best pictures from Final Say Brexit march Anti-Brexit supporters cheer outside parliament AP Best pictures from Final Say Brexit march A EU supporter waves flags REUTERS Best pictures from Final Say Brexit march Anti-Brexit supporters AP Best pictures from Final Say Brexit march Protesters shout and chant demanding a final say Getty Images Best pictures from Final Say Brexit march Police look towards protesters Getty Images Best pictures from Final Say Brexit march Pro-Brexit protesters outside the Houses of Parliament in London PA Best pictures from Final Say Brexit march People taking part in an Anti-Brexit, Let Us Be Heard march head to Parliament Square in London PA Best pictures from Final Say Brexit march People taking part in an Anti-Brexit, Let Us Be Heard march in Trafalgar Square PA Best pictures from Final Say Brexit march Anti-Brexit supporters cheer outside parliament AP Best pictures from Final Say Brexit march People taking part in an Anti-Brexit, Let Us Be Heard march past Trafalgar Square PA Best pictures from Final Say Brexit march Protesters 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Their early appearances on the campaign trail are likely to reveal their key messages in the coming weeks, with Labour focusing on its promise to take on “the elite” and the Tories personally targeting Mr Corbyn, including claiming he would seek a further delay to Brexit.

Mr Johnson will embark on three campaign stops across the east and southeast of England on Thursday, while Mr Corbyn will launch Labour’s campaign by delivering a speech in London.

Ahead of the visits, Mr Johnson said an election was “the only way forward” to break the Brexit deadlock despite MPs having urged him to bring forward the bill needed to enshrine his Brexit deal in law.

The deal was believed to have the support of a majority of MPs, but Mr Johnson decided instead to seek an early general election.

The prime minister said: “Today should have been the day that Brexit was delivered and we finally left the EU. But, despite the great new deal I agreed with the EU, Jeremy Corbyn refused to allow that to happen – insisting upon more dither, more delay and more uncertainty for families and business.

“We cannot continue along this path. I didn’t want an election – like the country I wanted to get Brexit done, but it is the only way forward.”

Mr Johnson will claim that a Labour government would result in the “toxic, tedious torpor of two more referendums – on EU membership and Scottish independence – thanks to Jeremy Corbyn’s incessant indecision”.

Mr Corbyn is expected to hit back during a speech in London alongside members of his shadow cabinet, in which he will attack Mr Johnson and his “born-to-rule Conservatives”.

Parliament overwhelmingly votes to hold an early general election

He will attempt to contrast this with his party’s commitment to “the overwhelming majority” and ask voters: “Whose side are you on?”

Mr Corbyn is expected to insist that the coming campaign is a “once in a generation chance to transform our country” and predict that “the elite” will “fight harder and dirtier than ever before” to stop him becoming prime minister.

He will name Mr Ashley, the Duke of Westminster, chemicals tycoon Jim Ratcliffe, media mogul Rupert Murdoch and hedge fund manager and Tory donor Crispin Odey as examples of the “bad bosses” and “big polluters” that Labour will take on.

He will say:“We put our faith in the British people’s spirit and commitment to community. It’s your country.

“That’s why we stand with you. We stand for the many. Boris Johnson’s born-to-rule Conservatives protect the privileged few. They’ve slashed taxes for the richest and vital services and support for everyone else – but real change is coming.”

Dismissing concerns that a winter election could lower turnout, which typically hurts Labour more than the Conservatives, he will add: “Boris Johnson thought he was being smart holding this election in a dark and cold December. He thinks you won’t go out to vote. He thinks you won’t go out to campaign.

“Labour will be out there in every city, town and village with the biggest and most confident campaign that our country has ever seen bringing a message of hope and change to every community.