Two defeats for the Conservative Party would suggest a poor showing could await at the next general election and add to political pressure on Rishi Sunak in the week the UK entered a recession.
If the Tories lose either seat, the Government will have clocked up more by-election losses in a single parliament than any administration since the 1960s.
And if they are defeated in both Wellingborough and Kingswood, it would be the third time that two by-elections have been lost on the same day during Rishi Sunak’s premiership.
The Tory majority in Kingswood is 11,200, while Wellingborough has a majority of 18,540.
Five-figure majorities being overturned would chime with predictions that the Tories are on course to endure a defeat to Labour at the next election, with Kingswood and Wellingborough having last returned Labour MPs under the leadership of Sir Tony Blair.
There has been speculation that a double defeat could even lead to more calls for Mr Sunak to go, although only two of his MPs have gone public to demand his resignation to date.