Josh Simons, now a minister, was given dossiers on journalists who were investigating Labour Together while he chaired the thinktank. The files, compiled by a PR agency, tracked reporters’ work on funding and influence. The revelation intensifies scrutiny of the party’s operations.

The PM urged Labour MPs to unite as he resists calls to dismiss chief of staff Morgan McSweeney following backlash over Peter Mandelson’s appointment. Downing St says nothing has changed, while critics warn the situation is untenable and demand a No 10 reset.

Labour MPs say Starmer’s premiership is in peril amid anger over appointing Peter Mandelson as US ambassador. Under pressure, No 10 will release papers on the decision. The row has strained party unity and fuelled talk of a leadership challenge if transparency proves lacking.

The Met has launched a criminal investigation into claims Peter Mandelson leaked Downing Street emails to Jeffrey Epstein. He has resigned from the Lords amid backlash as officers examine alleged unauthorised copies of official emails.