The prime minister has asked the foreign secretary to withdraw Peter Mandelson as ambassador.

We'll bring you more on this in the next few moments.

Image source, PA Media

While we wait for Foreign Secretary Yvette Cooper to take her seat in the Commons, let us remind you of what PM Keir Starmer said on this during PMQs yesterday.

Asked by Tory leader Kemi Badenoch how Peter Mandelson came to be appointed as US ambassador - and what he knew, and when - Starmer told the House: "A full due process was followed during this appointment, as it is with all ambassadors."

This came after Lib Dem leader Ed Davey asked Starmer if he was aware of the full extent of "compromising material" the White House may have on Mandelson.

Starmer also reiterated that he has "full confidence" in Mandelson, who was "repeatedly expressed deep regret" and is now "playing an important part in the US-UK relationship".

Jaws drop in Westminster, but No 10 insists due process was followedpublished at 10:41 BST 11 September

10:41 BST 11 September

Chris Mason
Political editor

This time last week, there was a drip, drip of revelations about the then-deputy prime minister and calls for her resignation.

Fast forward seven days, and there is a drip, drip of revelations about the UK's ambassador to the United States and calls for his resignation.

A cabinet minister's jaw drops when I tell them about the story.

For those who have kicked around at Westminster for a while, there is something familiar about it too.

Peter Mandelson twice lost his job in the cabinet two decades ago over his dealings with rich men.

Mandelson's friendship with the late Epstein has long been publicly known, so the key political questions are actually for the prime minister, in choosing to appoint him.

Downing Street is not currently providing straight answers when we ask whether these most recent revelations are a surprise to them and whether they know what may be still to come.

They insist "due process" was followed before Mandelson's appointment.

It would appear that either Downing Street was insufficiently curious or sceptical about the extent of Lord Mandelson's friendship with Epstein before giving him the job, or calculated that he would be so good in the role it would be worth soaking up any embarrassment the connection might cause them.

Or perhaps they hoped the embarrassing stuff would never come out.

• Read more here about the dramatic revelations

In some cases, situations may arise that MPs feel require an immediate response from the government.

In these instances, they can apply to ask an urgent question.

MPs make applications to ask these questions to the Speaker of the House of Commons in the morning. If the Speaker's office agrees that the matter is urgent, the MP can raise their issue in the chamber.

The relevant minister - in this case Yvette Cooper, in her new role as foreign secretary - must then attend the Chamber to address the issue and take questions from MPs.

Image source, PA Media

Foreign Secretary Yvette Cooper has been called to the House of Commons to answer an urgent question over Lord Mandelson's appointment as US ambassador.

Tory MP Neil O'Brien announced he would be asking the question in Parliament, adding "Starmer gave no answers yesterday [at PMQs], let's try again".

It all comes as the prime minister faces pressure over Mandelson's appointment after the emergence of fresh revelations about Mandelson's links to the late convicted paedophile Jeffrey Epstein.

In an interview with Harry Cole Saves the West, external, Lord Mandelson suggested further "embarrassing" exchanges would emerge. The Sun newspaper has reported he allegedly sent supportive messages to Epstein while he was facing charges in 2008.

Lord Mandelson told the BBC: "I relied on assurances of his innocence that turned out later to be horrendously false."

We'll bring you the latest from the House of Commons, and you can watch the urgent question exchange live at the top of our page.