UK's Conservatives say Labour heading for record win

Britain's Conservative Party have all-but conceded election defeat to Keir Starmer's Labour as voters head to polls on Thursday and warned the opposition party was on course for a record-breaking victory.

Opinion polls show the centre-left Labour Party is set for a big win that would end 14 years of Conservative government and hand Starmer the keys to the prime minister's Number 10 Downing Street office on Friday morning.

You Gov's final seat projection published on Wednesday put Labour on track to win a majority of 212 seats, the largest of any party in modern history.

Both Starmer and Conservative Prime Minister Rishi Sunak kicked off the final day of campaigning warning voters of dire economic consequences if the other man wins.

But, facing predictions of the worst result in the party's history, the Conservatives turned their focus to damage limitation, saying they needed to hang on to enough seats to provide an effective opposition to a Labour government.

"I totally accept that where the polls are at the moment means that tomorrow is likely to see the largest Labour landslide majority, the largest majority that this country has ever seen," Conservative minister Mel Stride told the BBC.

"What therefore matters now is what kind of opposition do we have, what kind of ability to scrutinise government is there within parliament."

Asked about Stride's comments, Sunak told ITV: "I'm fighting hard for every vote".

Britain's Prime Minister Rishi Sunak
Britain's Prime Minister Rishi Sunak says he's not giving up despite the dire polls. (AP PHOTO)

Sunak insisted Thursday represents a "pivotal moment" for the UK's future, as he claimed Labour would "wield their unchecked power" to increase taxes should they secure a "super majority".

"The reality is simple. If the polls are to be believed the country could wake up tomorrow to a Labour super majority ready to wield their unchecked power, put up everyone's taxes and leave the UK vulnerable to the threats we face at home and abroad," he said.

Sunak has sought to persuade voters that his 20 months in charge have set the UK economy on an upward path after the external shocks of COVID-19 and the war in Ukraine, and drawn a line under years of turmoil overseen by his Conservative predecessors.

However, the Rupert Murdoch-owned British tabloid newspaper The Sun endorsed Labour and Starmer, saying in an editorial published online: "It's time for a change".

"The insurmountable problem faced by the (Conservatives) is that - over the course of 14 often chaotic years - they have become a divided rabble, more interested in fighting themselves than running the country," the newspaper, which has backed the Conservatives at every election since 2010, said.

A polling station sign in London
Polling stations for the UK election open at 4pm AEST. (EPA PHOTO)

Labour's final campaign push focused on their fear that voters could see the result as a foregone conclusion and stay at home on Thursday, or register protest votes with smaller parties.

"I don't take anything for granted, I respect the voters, and I know that we have to earn every vote until 10 o'clock (Thursday) night and we will do that," Starmer said.

His campaign has been built around a one-word promise of "change," tapping into discontent at the state of Britain's stretched public services and falling living standards - symptoms of a sluggish economy and political instability.

"The choice today is clear," Starmer said. "Between a changed Labour Party that stands ready to restore politics to service and rebuild Britain. Or a Tory party that crashed our economy, left public services in ruin, and now wants to give us Liz Truss 2.0 with more unfunded spending promises.

"If the country votes for change with Labour, we'll get to work immediately with our first steps for change."

The Liberal Democrats are hoping to make gains, with leader Ed Davey saying: "This election is a historic chance to end years of Conservative chaos and save the NHS and care."

Polling stations open at 1600 AEST and close 0700 Friday AEST.

with PA