Former British Cabinet minister Lord Peter Mandelson has resigned from the House of Lords as the UK government referred material connected to his correspondence with late financier Jeffrey Epstein to police following an initial review of newly released documents.

The Cabinet Office’s assessment found that emails from the tranche of files issued by the United States Department of Justice contained information that was likely market-sensitive and related to Britain’s handling of the global financial crisis in 2008, prompting Downing Street to provide the material to the Metropolitan Police for further scrutiny.

Prime Minister Keir Starmer told a cabinet meeting that he was "appalled" by the disclosed exchanges and stressed the government’s cooperation with law enforcement as they examine whether the communications — sent by Mandelson during his tenure as business secretary under a previous administration — may have breached protocols on confidential information.

In the review, officials concluded that elements of the correspondence appeared to involve internal discussions about government policy on asset sales and economic stabilisation that would not ordinarily be shared outside official channels, leading to the formal referral to Scotland Yard.

The revelations have intensified pressure on Mandelson, a veteran figure in British politics who has occupied senior roles including business secretary, European commissioner and ambassador to the United States.

In addition to the police referral, Starmer’s government has asked officials to draft legislation that would enable expedited removal of Mandelson’s peerage — a rarely used measure requiring an act of parliament — underscoring the severity with which Downing Street views the situation.

Political figures across Westminster have expressed concern that the alleged leaks, if substantiated, could undermine confidence in the handling of state information by senior public office holders.

Mandelson’s resignation from the upper chamber, effective from 4 February, was announced by the Lord Speaker after weeks of mounting scrutiny.

The police have confirmed they are reviewing reports of alleged misconduct in public office as they determine whether the evidence meets the threshold for a criminal investigation.

Gordon Brown, who was prime minister when Mandelson served as business secretary, has also submitted information to assist the Metropolitan Police.

The unfolding developments mark a dramatic moment for one of Britain’s long-standing political operatives and have triggered broader debate about standards of public service and accountability in Westminster.