Voting ends Thursday in the leadership contest for Britain’s main opposition Labour party after a campaign dominated by the shock popularity of radical left candidate Jeremy Corbyn, who looks set to win.

Corbyn was attracting 53 percent support from those intending to vote, according to the most recent opinion polling from YouGov in mid-August, in a race whose result will be announced on Saturday.

His victory seems barely in doubt.

Corbyn, 66, is closer to European anti-austerity movements like Greece’s Syriza and Spain’s Podemos than Tony Blair.

He has become the darling of youthful and elderly Labour supporters as well as the powerful trade unions, all tired of the centrist policies of senior Labour figures like Blair, prime minister from 1997 to 2007.

Corbyn holds his final campaign rally Thursday in his home constituency in north London before a sell-out crowd, as has often been the case.

Grey-haired and with a close-cropped beard, often sporting sandals and looking like a retired teacher, he is neither a great orator nor a charismatic leader.

But faced with his campaign, the other three candidates — Andy Burnham, Yvette Cooper and Liz Kendall, all polished forty somethings advocating more centrist policies — have struggled to galvanise support.

“He has triumphed because he represents a rejection of conventional politics and also because Labour’s mainstream candidates failed to inspire excitement or hope,” Andrew Harrop, general secretary of left-wing think-tank the Fabian Society, told AFP.

“All the current evidence suggests that Corbyn has a very high chance of becoming Labour leader.”

Ironically, many commentators blamed Labour’s defeat under leader Ed Miliband by David Cameron’s Conservatives in May on a more leftist policy agenda pursued since 2010.

Four months later, the party looks set to vote for a far more left-wing figure, who is fond of bicycling around his constituency in London’s gentrifying Islington North, as its leader.

– Resistance v compromise –

Support for Corbyn may have been fuelled by the belief among some Labour voters that neither Burnham, Cooper nor Kendall would fare any better than Miliband did.

“They also feel a sense of despair at the prospect of at least a decade of Conservative rule, so they are choosing forthright, principled opposition over the compromise and discipline needed to prepare for government,” added Harrop.

The opening up of the vote — previously reserved for members of the party and trade unions — to anyone willing to pay £3 (four euros, $4.50) will also play a key role in the outcome, with over 600,000 people having applied.

Corbyn has run a good campaign, avoiding “difficult questions” on issues such as his views on the Middle East peace process and Britain’s place in the European Union, said Iain Begg, a professor at the London School of Economics.

A pacifist who wants to scrap Britain’s nuclear weapons, Corbyn believes Islamist movements Hamas and Hezbollah should be involved in Middle East peace talks.

This is a controversial view in a country where their military wings are listed as banned terrorist organisations.

And he seems to be keeping his options open on the EU ahead of Britain’s referendum on whether to leave the bloc, which must be held by the end of 2017.

Few believe he can ever be elected prime minister.

“With Corbyn, the chance that Labour could win in 2020 (the date of the next general election) is minimal,” said Begg.

But Harrop added that Corbyn’s legacy could be long-lasting if Labour splits between centrist and leftist elements.

“Corbyn could fail as a leader, in which case this may prove a temporary hiatus,” he said.

“However, the influence of his hard-left supporters could spread… in that case, Labour is likely to be out of power for a long time and may struggle to continue as a single party.”