The sacking of Azhar Ali as Labour’s candidate in the Rochdale by-election is the biggest disaster for Sir Keir Starmer in his nearly four years as leader of the party.

There will now be an almighty inquest into how a candidate who had made such comments about Israel and Gaza was selected for such a high-profile by-election.

Defending Rochdale was never going to be easy for Labour. Sir Tony Lloyd’s majority at the 2019 general election was 9,668, with the Conservatives in second place.

But the challenge from firebrand left-winger George Galloway and the constituency’s former Labour MP Simon Danczuk standing for Reform UK already presented difficulties.

But now Labour goes into the by-election on 29 February with no candidate, even though Mr Ali’s name will still be on the ballot paper, right at the top of the list in alphabetical order.

By-election results will provide important clues ahead of next general election

Should the Conservatives lose their two parliamentary seats in Kingswood and Wellingborough, the party will exceed its record of by-election defeats in a single parliament.

There is a chance too that the party could experience its worst ever defeat to Labour, of course to capture both seats.

But emerging divisions within Labour, over the conflict in the Middle East and now the ditching of the green investment pledge, could check its electoral progress.

The Conservative battle with Labour may ease, but the party is still threatened by strengthening support for Reform UK.

It is contesting both vacancies and targeting votes from disillusioned Conservatives.