Opposition leader Jeremy Corbyn said on Thursday he would defeat a "cosy cartel" at the heart of British politics, casting himself as the anti-establishment challenger in a snap election called by Prime Minister Theresa May.
The pledge, to be delivered via higher taxes on the wealthy and a crackdown on powerful corporations, set the tone for a campaign in which the veteran left-winger will try to defy opinion polls that point to a heavy defeat.
Battling to assert control over his own divided Labour Party as well as to convince the country at large, he sought to tap into widespread voter frustration with the political elite.
"It is the establishment versus the people and it is our historic duty to make sure that the people prevail," Corbyn told party supporters in central London.
"We don’t accept that it is natural for Britain to be governed by a ruling elite, the City and the tax-dodgers."
Conservative leader May sprang a major surprise on Tuesday by calling a June 8 election, three years ahead of schedule, to capitalise on a dramatic collapse in support for Labour and win a stronger mandate to boost her in complex divorce talks with the European Union.
While she tries to focus the debate on Brexit, Corbyn is looking to harness a powerful anti-establishment mood revealed by last year's EU referendum and echoed in the rhetoric of Bernie Sanders and Donald Trump during last year's U.S. election campaign.
"How dare they crash the economy with their recklessness and greed, and then punish those who had nothing to do with it?" he said, referring to the 2007-9 financial crisis.
"The British people know that they are the true wealth creators, held back by a system rigged for the wealth extractors."
He made only a passing reference to Brexit, widely described as Britain's biggest challenge since World War Two, saying he wanted to focus on life after leaving the EU.
"(May) will try to downplay the issues that affect people's lives every day and instead turn the election into an ego trip about her own failing leadership and the machinations of the coming negotiations in Brussels," he said.
Playing to simmering public anger about stagnant wages and businesses that pay low taxes, Corbyn said he would scrap planned cuts to corporation tax and reverse tax breaks for wealthy individuals.
"We will not longer allow those at the top to leech off those who bust their guts on zero-hours contracts, or those forced to make sacrifices to pay their mortgage or pay their rent," he said.
"Instead of the country's wealth being hidden in tax havens, we will put it in the hand of the people."
The political system was biased in favour of large companies, he said. "It is these rules that have allowed a cosy cartel to rig the system in favour of a few powerful and wealthy individuals and corporations."
Last year's vote to leave the EU split Labour's traditional supporter base, which is divided between typically pro-EU inner city voters, especially in London, and working-class voters in less affluent areas who voted for Brexit.
Corbyn, who voted to leave the EU's predecessor in 1975 but supported 'Remain' last year, has been criticised for muddling the party's position on Brexit and failing to effectively challenge May's push for a clean break with the bloc.
Corbyn denied a report published in The Times newspaper on Thursday which said his party could promise a public vote to approve the terms of Britain's EU exit. In a statement his spokesman said such a policy would not be in their manifesto.
A YouGov opinion poll carried out after the election was called showed May's Conservatives on 48 percent, with Labour trailing a distant second on 24 percent. By comparison, ahead of the 2015 general election, which the Conservatives won, polls showed the two parties were roughly level.
Analysis of polling data conducted by The Times newspaper showed May could win a landslide majority of 114 seats, up from 12 last time around.
May, who also backed staying in the EU but has since embraced the notion of life outside the bloc, is pitching her campaign on a promise of stable leadership to deliver a good deal for Britain from exit negotiations with Brussels.
If she can achieve a resounding election victory, that would limit the scope for parliament to block or water down her plan for Britain to quit the EU single market and to prioritise immigration control.