Privy Council minutes from Tuesday have now been published regarding Peter Mandelson.
“An Order striking out The Lord Mandelson from the List of Members of His Majesty’s Most Honourable Privy Council.”
The Order in Council stripping Mandelson of his peerage has also been published:

Mandelson is no longer the Right Honourable…
The government is briefing that legislation to strip Mandelson of his peerage won’t come until after the King’s Speech in May. No10 says this is because it is putting together wider legislation to remove peers in general. A manufactured delay…
Home Secretary Shabana Mahmood introduced her speech on migration reforms at the IPPR:
“There’s no denying we meet at a difficult time for my party.”