The Labour leader Jeremy Corbyn will try to turn the election campaign focus on to his pledge to build 500,000 units of social housing if elected

Staff in Labour headquarters are planning to strike if Jeremy Corbyn tries to cling on after a large defeat.

The threat came as Matt Zarb-Cousin, a former media aide to Mr Corbyn, criticised Labour HQ workers, accusing them of “endless leaks” that made it difficult to function.

Officials at the party’s headquarters at Southside in Pimlico, half a mile from the Houses of Parliament, fear that the leader will refuse to go even if he loses dozens of seats on June 8.

Most Labour staff were appointed before Mr Corbyn came to power and, while usually neutral in party contests and over political disputes, almost none shares his politics.

Two sources said that party officials had discussed striking to send a message that he must