The former top civil servant in Britain’s foreign office, who was fired by Prime Minister Keir Starmer last week, said on Tuesday that Mr. Starmer’s office had a “dismissive attitude” about the security vetting of Peter Mandelson, an associate of Jeffrey Epstein who became ambassador to the United States despite concerns raised during the vetting process.

The former civil servant, Olly Robbins, testified in Parliament that he and other officials in charge of deciding whether to grant Mr. Mandelson a high-level security clearance were working in “an atmosphere of pressure” to ensure that nothing got in the way of Mr. Mandelson’s appointment.