Jeremy Corbyn is railing against "cuts, closures and poverty". He's campaigning to build more homes, and to fight fewer wars. He's condemning the Tories for creating a "divided and unequal society".

But these are snippets not from his 2019 bid for Downing Street. They were his slogans in 1983, when he first ran for Parliament.

The simple fact is the Labour leader has never changed his views.

In the late 1970s and 1980s he and his staunch left-wing colleague John McDonnell, now the shadow chancellor, promised a revolution to upend the Western capitalist order.

And yet, in 2015, as he was fighting to take over the leadership of the party, he was pledging the same: "Capitalism is in its death throes!"

It's not mere sloganeering. His policy agenda over the past year has been: renationalise British utilities and trains, cap all wages, and force large companies to transfer 10 per cent of their equity to their employees.

It says something about the depths of the austerity cuts in Britain that Mr Corbyn was not only backed into the Labour leadership, but went on to gain the largest increase in the party's share of the vote in the 2017 election since World War II.

And in the torrid political climate that followed, many would have expected Labour to romp home this time around. Over the past three years, the Conservative Party has imploded, with grave wounds struck to much of its credibility.

Once Theresa May was torn down and replaced by Boris Johnson, a man with a public reputation as a liar, perhaps in any other generation of politics Labour would have been a shoo-in.

But this time around, Mr Corbyn has been found deeply unelectable.

Chris Curtis, the political research director at YouGov, the UK's biggest pollster, summed it up for the ABC:

"The chances of the Labour Party getting a majority are about as close to zero as it's possible to get."

A poll carried out in September for London's Evening Standard newspaper, which is edited by former Conservative chancellor George Osborne, gave Mr Corbyn a net satisfaction rating of -60.

Ipsos Mori found only 16 per cent of voters were satisfied with Mr Corbyn's performance, compared with 76 per cent who were dissatisfied.

That made him the most unpopular opposition leader since Ipsos Mori began polling 45 years ago.

Former Labour leader Michael Foot had an approval score of -56 in 1982 — a year before he lost in a landslide to Margaret Thatcher.

The stench of anti-Semitism

After his early victories, secure in the leadership, Mr Corbyn and his allies cemented control of the party apparatus around him. A hardcore of believers, and thousands of new members, electrified by Mr Corbyn's radicalism, shifted the Labour Party to the far left. The checks and balances steadily eroded.

Which is why the firestorm of anti-Semitism has been impossible for Mr Corbyn to extinguish.

Despite his repeated promises to crack down on the problem, an anti-Jewish culture has flourished under his watch. Almost weekly there have been revelations of anti-Jewish words and actions from his party members, and there have been repeated accusations, all denied, that he himself harbours anti-Semitic sentiments.

Jeremy Corbyn has been criticised for failing to eradicate anti-Semitism from the Labour Party. ( AP: Chris Radburn )

Mr Corbyn has now been publicly condemned by Britain's Chief Rabbi and by the Simon Wiesenthal Centre. A wave of MPs have quit the party in disgust over the issue.

On Wednesday, a group of 15 former Labour parliamentarians published a full-page advertisement in newspapers across the north of the country — Labour's heartland — castigating Mr Corbyn for his failure to stamp out anti-Semitism and for being "weak on national security".

Brexit uncertainty

But perhaps most critical to Mr Corbyn's flailing popularity is Brexit.

Even though this election is seen by many as a last-chance opportunity to decide whether the UK really should leave the EU, Jeremy Corbyn has yet to articulate a clear position on that question.

His policy is to renegotiate a new deal and take it back to the people for a confirmatory vote. But for many, that is simply insufficiently clear a position for a prospective prime minister.

"There's a saying," Mr Curtis said, "the soufflé doesn't rise twice".

"What we've seen happen with Jeremy Corbyn is a massive surge in support for him in the last election campaign but ever since then he's become more and more unpopular.

"[It's] for various reasons, [but] the most important one being what the public perceive is a wishy-washy position on Brexit.

"Because he's trying to balance between his Leave and Remain voters, he often hasn't been forthcoming in saying what he thinks about the most important issue facing the country."

Prime Minister Boris Johnson and Labour Opposition Leader Jeremy Corbyn are going head to head in the general election. ( Reuters: Toby Melville )

Mr Corbyn is gunning for a much lower threshold than Boris Johnson.

All he needs to do is deny the Tories a majority, and he will be a chance to lead a minority coalition of parties.

From there, he'll be hoping to plot again his path to the social revolution he's worked his life to achieve.