Departure of political strategy director Paul Ovenden is yet another setback for PM after Mandelson and Rayner exits

A senior adviser to Keir Starmer has resigned after it was revealed he sent inappropriate messages about the Labour MP Diane Abbott eight years ago.

Paul Ovenden quit on Monday as the prime minister’s director of political strategy after details emerged about a sexually explicit WhatsApp conversation he had in 2017.

His resignation is another setback for the beleaguered prime minister, who has also lost his deputy prime minister, Angela Rayner, and his Washington ambassador, Peter Mandelson, to separate scandals in the last two weeks.

The messages show Ovenden and a friend joking about a party that Ovenden had attended the night before at which attenders had joked about having sex with Abbott, the Labour MP who is the longest-serving woman in the Commons.