POLITICS is a murky business, but the defection of a right-wing Conservative MP to the Labour Party creates a new order of murkiness.

Keir Starmer obviously thought that accepting the Dover MP Natalie Elphicke as she crossed the floor of the House of Commons would show how rotten and sinking Rishi Sunak’s Conservative Party has become, and her criticisms are stinging: she says the Conservative government has become “a byword for incompetence and division”.

However, only a few months ago, Ms Elphicke was saying equally barbed things about the Labour Party and Sir Keir himself, whom she ridiculed as “Sir Softie”. She voted against Labour’s policies, most notably over the fire and rehire tactics of a ferry company, and, only a few years ago, she clashed with footballer Marcus Rashford when he emerged as a popular campaigner over free school meals.

And then there’s the strange story about how Ms Elphicke gained her seat after her husband, the sitting Conservative MP and self-proclaimed “naughty Tory”, was found guilty of three counts of sexual assault. A Commons committee even recommended that she be suspended from the House for a day for attempting to influence the judge who was sentencing him.

Labour, as the opposition, has to cause as much mayhem for the Government as possible, but it can’t expect to win just because the Tories are hopeless. It has to stand for something, yet the only thing Ms Elphicke appears to have in common with Labour MPs and activists is her low opinion of Rishi Sunak.

This is not a clear cut, headline-grabbing win for Mr Starmer. It murkies the political waters, and if Ms Elphicke were ever to receive an honour for crossing the floor, it would look grubbier still.