By Ben Bloch, political reporter
In the wake of a series of revelations about Peter Mandelson's relationship with Jeffrey Epstein, particularly during the period he was de facto deputy-PM in Gordon Brown's government, Sir Keir Starmer is facing calls to pass legislation to kick him out of the House of Lords.
Lib Dem leader Sir Ed Davey has said it is "the very least they can do for the victims and survivors" of the convicted paedophile, and the SNP say they have a bill "ready to go" for the government to advance.
So why hasn't No 10 done it?
Although the PM's team is clear that they want Mandelson gone, there is no mechanism to remove a peerage once it has been awarded.
The only way to remove someone from the House of Lords is through an Act of Parliament, and although that was done in 1917 for a group of "enemies" of the UK in the First World War, it has never been done for an individual peer.
There are fears in No 10 that if they did table such legislation, it could get bogged down by amendments from peers who do not want to set a precedent that the government of the day could use against any peer they deem has behaved badly.
The Conservative Party - which has the largest number of peers in the upper chamber - is effectively backing that position.
Shadow cabinet minister Alex Burghart said this morning that he believes in "due process", and if Mandelson is found to have broken the law, he would support moving to remove the disgraced peer.
Leader Kemi Badenoch was also clear to broadcasters this morning that if a peer has been "convicted of criminal offences, then yes, I don't think people should be sitting in the Lords".
Watch: Why hasn't Mandelson been stripped of peerage?
No 10 is certainly not ruling out tabling legislation to remove Mandelson directly, but they believe that getting agreement from all parties on reforms to the process for removing a peer is the quickest solution (barring the sacked former ambassador resigning, which is the preferred expedient option).
Sources have told Paste BN that the government is working "at pace" to reach an agreement with the other parties in the Lords, but the longer it takes, the more pressure increases on No 10 to take unilateral action, which they believe has its own risks.