Moderate Labour MPs, angered by plans by Jeremy Corbyn’s allies to deselect them, are poised to stand down, triggering a string of potentially damaging by-elections.

A party insider said MPs were prepared to quit after Corbyn’s allies signalled that they wanted to purge critics of the leader and change party rules to strengthen their position.

The news comes just days after the MP for Liverpool Wavertree, Luciana Berger, was threatened with deselection by hard-left activists unless she apologised for criticising Corbyn.

The insider said: “Any attempt by the hard left to increase their stranglehold over the party will backfire. There are a number of older MPs who are serving their last term and were planning to stand down before the snap general election who would