LONDON, United Kingdom (AFP) — Veteran socialist Jeremy Corbyn was elected leader of Britain’s main opposition Labour party yesterday in a landslide victory that gives the country its most left-wing political leader in decades.

The 66-year-old, whose policies have been compared to those of Greece’s Syriza and Spain’s Podemos, was named leader after clinching 59.5 per cent of the votes cast by Labour supporters.

The new chief could divide Britain’s main opposition party and he immediately faced resignations from the shadow cabinet amid warnings from party grandees that a Corbyn-led Labour would be consigned to electoral oblivion.

In his victory speech to the party faithful, Corbyn slammed Prime Minister David Cameron’s Conservatives for presiding over “grotesque levels of inequality” and for creating “an unfair welfare system”.

As the win was announced in a conference centre in Westminster, supporters chanted “Jez We Can!” while centrist Labour figures looked shell-shocked.

Corbyn later thanked his supporters in a nearby pub, The Sanctuary, where he joined in a rendition of the traditional Labour anthem The Red Flag.

“It’s a fantastic moment for change in Britain,” he told reporters as he arrived at the venue.

The veteran MP has said he will oppose Britain joining in air strikes against the Islamic State Group over Syria and has been ambiguous on his stance on an upcoming referendum on Britain’s EU membership.

Addressing tens of thousands of people at a pro-refugee rally in London later on, Corbyn alluded to Cameron’s reference to air strikes as part of the solution to the refugee crisis.

“Tragically wars don’t end when the last bullet is fired… Surely our objective ought to be to find peaceful solutions to the problems of this world,” said Corbyn, a founder of the Stop the War coalition that organised mass rallies against the Iraq War.

As support for anti-austerity parties swells across Europe, Greece’s hard-left Syriza welcomed Corbyn’s election, saying it represented a “message of hope” and would bolster a “pan-European front” against crippling spending cuts.

Spain’s leftist Podemos leader Pablo Iglesias tweeted that Corbyn’s triumph was “a step forward towards a change in Europe for the benefit of the people”.

In a campaign driven by protest groups and trade unions, Corbyn comfortably beat the more centrist Yvette Cooper, Andy Burnham and Liz Kendall, who all had far stronger support from fellow Labour MPs.

Corbyn has electrified Labour’s leadership race, which was triggered by the resignation of Ed Miliband after he lost May’s general election to Cameron’s centre-right, pro-austerity Conservatives.

His chances at the next 2020 general election are thought to be slim but the Conservative Party was quick to react to his victory with a statement calling him a threat to national security.

“Labour are now a serious risk to our nation’s security, our economy’s security and your family’s security,” Michael Fallon, the defence minister, said in a statement.

Labour was thrown into turmoil by Cameron’s shock election win because his previous coalition administration, which shared power with the centrist Liberal Democrats, had implemented billions of pounds of deeply unpopular austerity cutbacks.

Corbyn’s policies include spending more on public services like schools and hospitals, scrapping nuclear weapons, renationalising industries like the railways and involving Islamist groups Hamas and Hezbollah in Middle East peace talks.

He drew strong support from students who had never voted before as well as from older people disillusioned with Labour since it moved to the centre-ground of British politics under former Prime Minister Tony Blair in the 1990s.

The bearded, grey-haired vegetarian crammed in 99 campaign appearances, eschewing soundbites and usually wearing sandals and carrying a cup of tea.

While many Labour MPs praised his personal qualities, several indicated they would not be prepared to serve in the shadow cabinet under his leadership.

Labour health spokesman Jamie Reed posted his resignation letter on Twitter, citing Corbyn’s anti-nuclear policies as “fundamentally wrong”.

Tony Blair — Labour’s most electorally successful leader who is now deeply unpopular over Iraq — warned before the result was announced that Corbyn’s victory would split Labour and consign the party to electoral oblivion.

Blair referred to Corbyn’s policies as “fantasy”.

Corbyn however has won the Labour crown by a more impressive margin than Blair, who won 57 per cent support at his leadership contest in 1994.