THE UK government could be on track for the most spectacular political backfire since Brexit, according to a poll just one week out from the general election.

YouGov data released on Wednesday showed Labour leader Jeremy Corbyn could pick up enough seats to force a hung parliament in a move that would be disastrous for Conservative Prime Minister Theresa May.

While the constituency-by-constituency model has a wide margin of error, it shows the Conservatives could lose 20 seats while Labour gained up to 30 due to a significant “churn” in voters. On the other hand, it could show an increased majority for the Conservatives as Labour loses out, YouGov chief executive Stephen Shakespeare said.

“The data suggests that there is churn on all fronts: the Conservatives, Labour and the Liberal Democrats are all likely to lose and gain seats,” he said.

While the poll is considered a “snapshot” of opinion based on the last week, it’s one of seven recent counts that show Labour closing the gap on the Conservative party ahead of the election that will take place on June 8.

The tightening numbers are a slap in the face for Conservative Prime Minister Theresa May who called the vote in a bid to strengthen their hand in Brexit negotiations when the Tories had a seemingly unassailable lead of more than 20 points

The calculated risk seemed like an easy win against the party led by career backbencher Jeremy Corbyn. The hard left-wing MP for Islington has been a hugely polarising leader who has attracted thousands of new supporters but forced cabinet ministers to resign over his leadership abilities.

Up until the last week, he has been widely ridiculed as unelectable and languished in preferred Prime Minister polls. However the publication of party manifestos proved a turning point after Theresa May was forced to back down on a “dementia tax” for elderly care that undermined her self-proclaimed “strong and stable” leadership with a “weak and wobbly” catchcry that took off on social media.

Meanwhile, Mr Corbyn pledged free university tuition, school lunches and privatisation of the railways, water and postal system funded by massive tax raises in moves that have gained support from anti-austerity sections of UK society.

Kings College London Professor of European Politics Anand Menon said a win for Corbyn would be a “massive failure for Theresa May” and have similarities with the election of Donald Trump.

“It’ll be like Trump in the narrow sense of learning something everyday,” he said. “I’m not saying he’s like Trump, but it will be that same sense of ‘oh my god how will he govern?’”

“One of the reputations he’s gained in opposition is of being rather disorganised and not having a very professional team around him. It’s impossible to know what’s going to happen. We’ve not seen this amount of electoral instability for a long time.”

Financial markets have already been jittery over the prospect of a reduced majority for the Conservatives particularly as “no one will have the first clue how [Corbyn] will govern,” he said.

It could also spell the end of Theresa May, who has a “high bar” for success.

“One of the side effects of running an essentially presidential campaign is if you lose, you’ve got nowhere to hide. She will be over and done with, her political career will be essentially over.”

Mrs May has downplayed suggestions the poll will affect the final result.

“The only poll that matters is the one that’s going to take place on June 8 and then people will have a choice as to who they want to see as leader, who they want to see as prime minister taking this country forward in the future, me or Jeremy Corbyn,” she said.

“I have the plan for the Brexit negotiations but I’ve also got a plan to build a stronger and more prosperous Britain and I’m confident we can do that because I believe in Britain and I believe in the British people.”

YouGov analyst Joe Twyman said so far “underlying data” favours the Conservatives in the campaign that has had three acts.

“They still enjoy a substantial lead on issues such as security, the economy and Brexit, while Theresa May is more favoured, by some distance, over Jeremy Corbyn when it comes to who the public think would make the best prime minister,” he said.

“The story of the 2017 general election campaign may well have a fourth (or even fifth) act still left to unfold. And the coming days could yet mean it emerges as a thriller, a tragedy, a comedy, a farce or something else entirely.”