Tiwa Adebayo

But at a meeting of senior cabinet ministers yesterday, Starmer said he wouldn't go without a leadership fight.

Deputy Prime Minister David Lammy was at that meeting and is backing his boss.

But unlike Lamy, other senior ministers including Ed Miliband and Shabana Mahmood refused to speak to the media.

A letter is said to be circulating in Parliament with more than 100 MPs backing Starmer to stay.

The US ambassador to the UK, Warren Stevens, told LBC's Andrew Marr that changing leaders makes it harder to build relationships.

U.S.

Ambassador Warren Stevens speaking on LBC.

One of Starmer's potential challenges, Health Secretary Wes Streeting, has been seen entering and leaving 10 Downing Street after just 15 minutes this morning.

The ongoing leadership speculation comes as the government plans to set out its legislative agenda in the King's speech later today.

Investor concerns over Keir Starmer being replaced by a more left-wing leader were further underscored in market moves over the past 24 hours.

Shares in British banks Lloyds, NatWest and Barclays all fell sharply yesterday after JP Morgan analysts warned banks could face higher taxes.

They've recovered some of those losses today.

Speaking exclusively to Bloomberg, CEO Jamie Dimon went further, warning that any hikes could prompt JP Morgan to scrap plans to invest billions in a new London headquarters.

The boss of the world's biggest bank added that he thinks the world of the UK's finance minister, Rachel Reeves, and described Keir Starmer as a very smart guy.

In the same interview, Diamond also weighed in on US-EU trade tensions, calling for a resolution that benefits both sides.

JP Morgan's Jamie Dimon has long voiced concerns about Europe, saying in December that the continent has a real problem.

Oil shipments from Iran's main export terminal appear to have come to a prolonged halt for the first time since the beginning of the war.

Satellite images reviewed by Bloomberg show no oil tankers leaving Karg Island on three of the past seven days.

Here's Bloomberg's Stuart Livingston-Wallace.

Bloomberg's head of Middle East and North Africa coverage, Stuart Livingston Wallace, there.