Five questions awaiting Starmer as he faces Commons over Mandelson scandal

Under the code, the minister in question should correct the record in Parliament "at the earliest opportunity". Opposition party leaders say Sir Keir should have done this at PMQs last week, the day after he said he found out about the red flags.

Sir Keir told journalists that having found out the information on vetting last Tuesday, he asked his civil servants to provide full details so he could ensure accuracy when he returned to the Commons to answer questions from MPs on Monday.

There are sure to be questions about this six-day delay, although we know the prime minister was in Paris on Thursday for a pre-scheduled meeting of global leaders on the Iran war, and the next parliamentary sitting was Monday.

The remaining documents relating to Lord Mandelson's vetting and appointment are set to be released imminently.

They were initially withheld on the orders of the Metropolitan Police, which is investigating Lord Mandelson for potential criminal activity.

The documents also need to be inspected by the Intelligence and Security Committee of cross-party MPs, which is trying to balance allowing as much information as possible into the public domain without compromising national security.

Conservative leader Kemi Badenoch has demanded the papers be released by the end of the week.

In November, the then head of the civil service, Sir Chris Wormald, said Lord Mandelson was not formally interviewed for the role of US ambassador.

Sir Chris said Lord Mandelson was not directly asked in person about any conflict of interest, but instead needed to fill in a form aimed more at potential financial conflicts. This process has now been changed.

Details of the due diligence checks made before Lord Mandelson's appointment, which were carried out by the Cabinet Office on behalf of Number 10, are still to emerge. The publication of these checks were specifically demanded by the Liberal Democrats on Sunday.

However, Sir Chris told MPs in November that the document did contain an "initial assessment" of mitigations around potential professional or financial relationships and noted the inclusion of "a general reputational risk" linked to Epstein.

This scandal has dragged on for months and has so far cost Sir Keir his US ambassador, his chief of staff, and the head of the Foreign Office, Sir Olly Robbins, who was ousted on Thursday.

Sir Olly will appear before the Foreign Affairs Committee on Tuesday to give evidence on how Lord Mandelson's clearance was handled.

The committee chair, Dame Emily Thornberry, said she felt she had been "misled" by Sir Olly when he first appeared at the committee in November last year.

He will be expected to explain whether red flags about Lord Mandelson's appointment were ignored, and if so who by and why.

He is also expected to be asked whether Foreign Office staff were leaned on in any way by Number 10.

And then there is the question of whether Labour backbenchers, returning from a week on the campaign trail for local elections, will rally behind their leader.

The remaining documents linked to Lord Mandelson's vetting will be released at some point in the next few weeks, and the possibility of a criminal trial remains.

Sign up for our Politics Essential newsletter to read top political analysis, gain insight from across the UK and stay up to speed with the big moments. It'll be delivered straight to your inbox every weekday.