LONDON -- British Prime Minister Keir Starmer will face a vote to decide whether he will be investigated over claims he misled the parliament regarding the vetting of former British Ambassador to the United States Peter Mandelson, British House of Commons Speaker Lindsay Hoyle said on Monday.

Hoyle said the parliament will hold a debate on Tuesday and vote on whether the matter should be passed on to the Committee of Privileges in the House of Commons for further investigation.

Downing Street dismissed the Conservative Party's proposed vote as a "desperate political stunt," according to media report, adding: "Their claims have no substance."

It was revealed in mid-April that before Mandelson took up his role, he had been denied a clearance in January 2025 after a developed vetting process, a confidential background check by security officials, but the decision was overruled by Britain's Foreign Office.

While Starmer admitted he was only aware of the situation on April 14, saying it was "completely unacceptable," Conservative Party leader Kemi Badenoch accused him of breaching the Ministerial Code by failing to inform parliament in a timely manner about the vetting scandal.

Mandelson was sacked as Britain's chief diplomat in Washington in September 2025 after revelations about his friendship with convicted sex trafficker Jeffrey Epstein.

Earlier this year, he was briefly arrested following a criminal investigation into his alleged misconduct in public office, including the possible disclosure of market-sensitive information.