Voters will head to the polls in Chester today to decide the city's new MP in a by-election triggered by the resignation of Labour's Christian Matheson.
Last month Mr Matheson quit the Commons and was suspended from the party over "serious" sexual misconduct.
Today's vote will be the first by-election since June where the Tories suffered a historic defeat in the Devon seat of Tiverton and Honiton - despite a 24,000-strong majority - to the Liberal Democrats.
It will also be the first test of public opinion at the ballot box since Rishi Sunak became Prime Minister in the aftermath of Liz Truss's disastrous mini-Budget.
The fiscal event led to turmoil in the markets, the Tories' poll rating collapsing, and Ms Truss becoming the shortest serving PM in British history.
The North West seat of Chester has been a safe Labour constituency in recent years and Keir Starmer will be aiming to capitalise on the Conservative woes.
Few are expecting any upset when the results are declared on Friday morning but Labour will be hoping to increase its vote share - reflecting the party's double-digit lead in the national polls.
At the last general election in 2019 Labour retained the seat with a majority of 6,164 votes with 49.6% of the vote share.
The leading pollster Professor Sir John Curtice said the most recent and similar comparison was a by-election held in Birmingham Erdington in March 2022.
Labour was defending the safe seat and increased its vote share by 5%.
"That was post-Partygate - Partygate had already kicked in - but way before Liz Truss," he told The Mirror.
While he said Labour tends "not to do as well" in safe seats the party is defending in by-elections he pointed to the national polls.
"Labour at the moment are running at about 48%, which is 15 points up on where they were last time.
"Labour would expect to be between 55 and 60% in this by-election for it to be a performance that would demonstrate that they are indeed stronger than they were at the time of the last by-election in a Labour held seat".
Shadow Chancellor Rachel Reeves said this week the by-election is a chance for voters to "send the Tories a message".
"Their cost-of-living crisis, their increases in taxes and their running down of public services is just not acceptable".
