Labour MP Andy McDonald has said there is “widespread revulsion” in the party over Lord Mandelson’s links with convicted paedophile Jeffrey Epstein, amid growing calls for him to be sacked.

McDonald called for Mandelson to stand down “immediately” as the UK’s ambassador to Washington, following fresh revelations in emails about his relationship with Epstein.

The Conservatives are stepping up pressure on Sir Keir Starmer to sack Mandelson, with an urgent question from MP Neil O’Brien due in Parliament shortly.

Home Office Minister Mike Tapp this said the prime minister continues to have “confidence in Mandelson” and his abilities as ambassador, adding the “disturbing” emails made him “shudder”.

Lord Mandelson is reported by Bloomberg to have told Epstein to “fight for early release” shortly before he was sentenced to 18 months in prison, and told him, “I think the world of you” the day before he began his sentence for soliciting prostitution from a minor in June 2008.

McDonald told BBC Radio 4’s Today programme: “I’m afraid if he [Mandelson] doesn’t do the right thing and resign today then the prime minister should sack him.”

The PM will face “inescapable” questions about his own judgement in appointing Mandelson, said McDonald, who suggested the vetting process may have failed.

Asked how Labour MPs were feeling about Mandelson, McDonald said: “It is widespread revulsion that we, by association, being in the same party, are being brought under the microscope for something that he has done.

“There isn’t anybody in the Labour Party who is supporting Peter Mandelson today and the Prime Minister’s got to hear that and understand that he’ll weaken his position if he continues to support him.”

The MP for Middlesbrough and Thornaby East dismissed concerns sacking Mandelson could damage to relations with US President Donald Trump and urged Sir Keir to show he had a “moral compass” to honour Epstein’s victims.

Asked what he thought of Mandelson’s emails to Epstein on BBC Breakfast, Home Office Minister Mike Tapp said the emails made him physically “shudder”, adding: “I find it disturbing, those sorts of emails in honesty.”

Tapp, who has worked for the National Crime Agency, said: “I have arrested these vile paedophiles and had to meet many of the victims of these crimes, so it’s really important that’s clear.”

However, asked whether the government was reviewing Mandelson’s future as ambassador, Tapp said “the prime minister has confidence in his ability”

he added that that “the work he is doing in America is very important”, stressing the recent UK-US trade deal as well as their defence relationship around the threat from Russia.