Voters are heading to the polls in Wellingborough and Kingswood, where Labour are hoping to overturn Conservative majorities and eat into Rishi Sunak’s Commons advantage.
The by-elections are being contested on Thursday in both seats, where the Tories hold majorities in the tens of thousands.
It will indicate public mood around the time Britain has entered another recession ahead of a general election - which is set to be contested later this year.
Tory defeat in either constituency means that the Government has clocked up more by-election losses in a single parliament than any administration since the 1960s.
But it is a third by-election, taking place later this month in Rochdale, that has got headlines this week.
Labour earlier this week came under fire for standing by Mr Ali, after he allegedly told a Lancashire Labour party meeting that Israel had "allowed" the deadly attack by Hamas gunmen on October 7.
But the party has taken back its support and Mr Ali is now reportedly suspended, pending information.
A Labour Party spokesperson said: "Following new information about further comments made by Azhar Ali coming to light today, the Labour Party has withdrawn its support for Azhar Ali as our candidate in the Rochdale by-election.
"Keir Starmer has changed Labour so that it is unrecognisable from the party of 2019.
"We understand that these are highly unusual circumstances but it is vital that any candidate put forward by Labour fully represents its aims and values.
"Given that nominations have now closed, Azhar Ali cannot be replaced as the candidate."
A Lancashire county councillor and former government adviser who was made an OBE in 2020 for public service, Mr Ali apologised for his remarks on Sunday (February 11).
“I apologise unreservedly to the Jewish community for my comments, which were deeply offensive, ignorant and false,” he said.
“Hamas’s horrific terror attack was the responsibility of Hamas alone, and they are still holding hostages who must be released.”
Conservative MPs had called for him to be removed as a candidate for the Rochdale by-election.
Labour will not be able to withdraw Mr Ali as its candidate because the deadline passed on February 9.
Where and when are the next by-elections in 2024?
The Rochdale by-election will take place on Thursday, February 29.
There will be two by-elections before that – in Kingswood and Wellingborough, on Thursday, February 15.
A sexual misconduct incident involving MP Peter Bone lost the Conservatives the Wellingborough seat and the chief whip issued a writ for an election to replace him.
At the start of January, the Conservatives controversially selected Helen Harrison, the reported girlfriend of Mr Bone, as their candidate in Wellingborough.
Additionally, Chris Skidmore, the MP for Kingswood, who resigned in protest of the Government's intentions to increase oil and gas production in the North Sea, will be replaced on the same date.
Blackpool South MP Scott Benton, who was caught in a lobbying sting, faces a 35-day suspension and an as-yet-to-be-announced by-election.
The Times caught the MP offering to lobby ministers and table parliamentary questions on behalf of gambling investors.
Mr Benton could lose the whip if the Commons backs the punishment.
Labour won two by-elections from the Conservative Party last year to further bolster hopes of success at the next general election.
One of Britain’s leading election experts, Professor of Politics at Strathclyde University Sir John Curtice, said the Tories could suffer a bigger defeat than Tony Blair’s 1997 landslide victory.
Labour won Mid Bedfordshire in October, overturning a post-war record 24,664 majority. In the same month, they enjoyed another huge overturn of 19,600 to win Tamworth.
The Staffordshire seat had been held by the now disgraced Chris Pincher, with Sarah Edwards the new MP. Labour’s Alistair Strathern won what was Nadine Dorries’ old seat in Mid Bedfordshire.
Leader Sir Keir Starmer claimed Labour was “redrawing the political map” by taking seats that had been comfortably Conservative before the general election.
The date for the next general election has not yet been confirmed but it will need to be held in January 2025 at the very latest.
When do by-elections take place?
A by-election takes place when one of the following happens. An MP:
resigns or dies
is declared bankrupt
takes a seat in the House of Lords
is convicted of a serious criminal offence
The by-election timing is determined by law. The Representation of the People Act 1983 specifies that a by-election must be held within a specific timeframe after the seat becomes vacant. This timeframe is usually between three to six months, but it can vary depending on the circumstances.
Once the by-election is called, candidates from political parties and/or independent candidates have the opportunity to stand for election to fill the vacant seat. The candidate who receives the most votes in the by-election is elected as the new MP for that constituency.
Upon winning the by-election, the newly elected MP assumes their responsibilities in the House of Commons. They participate in parliamentary proceedings, vote on legislation, represent the interests of their constituents, and may join committees or take on other roles within Parliament.
It's important to note that the winning MP serves out the remainder of the term of the seat that was vacated — until the next general election is held. At the general election, which occurs every five years under the Fixed-term Parliaments Act 2011, the seat will be contested again along with all other seats in the House of Commons.