In a dramatic twist, No 10 has rallied behind Prime Minister Sir Keir Starmer, warning that any leadership challenge could ripple through the markets.

Downing Street has insisted Sir Keir Starmer will fight any challenge to his leadership (Image: Getty)

No 10 has come out swinging in defence of embattled Prime Minister Sir Keir Starmer, warning plotters that any attempt to oust him could send shockwaves through the markets.

Downing Street insiders have taken the unusual step of deliberately intervening to shore up Sir Keir’s position, amid swirling rumours that a leadership challenge could be launched as early as the Budget.

The rare show of support comes as Sir Keir’s allies point the finger at Health Secretary Wes Streeting and Home Secretary Shabana Mahmood, accusing them of secretly manoeuvring to take the top job.