Dan Jarvis, the Labour MP and Sheffield city region mayor, has called for a “clean break” with the era of Jeremy Corbyn and refused to rule out running for the party leadership.

Jarvis delivered a scathing assessment of Corbyn’s four years in charge, saying the party had not delivered a credible leader or programme for government at the election.

Labour leadership contest: who's in and who could join them? Read more

Asked if a significant break with Corbyn was needed, he said: “Yes. The leadership of the past few years has not been successful in winning elections. We’ve lost twice now. And what we’ve got to do is listen to what people have been saying right around the country.

“In my own region of South Yorkshire, people felt they didn’t think the Labour party spoke for them any more. In a traditional Labour heartland, too many people said they weren’t prepared to vote Labour this time. We’ve got to listen to those people

“Yes it is about the leader. It’s about having someone who you can credibly present to the country as a prime minister. But it’s also about the team of people around them, it’s about the shadow cabinet, it’s about the closest trusted advisers, it’s about having a top team that understands the challenges people face and can credibly project a programme of government to the country.”

Jarvis gave his analysis on the BBC’s World at One programme, using a very different tone from leadership contenders so far, such as Keir Starmer and Lisa Nandy, who have generally been cautious about criticising Corbyn.

Play Video Boris Johnson and Jeremy Corbyn's Christmas messages compared – video

Corbyn still enjoys support among many of Labour’s 550,000 members who will vote for a new leader and it is not yet clear what the appetite is among the party’s base for a new direction.

On his own ambitions, Jarvis said he was “not considering it at the moment” because of his other job as mayor of Sheffield city region, but he later twice refused to rule it out and said he wanted to step up and play a role in rebuilding Labour.

He told the BBC: “There are some very simple things you have to do: you have to have a credible leader, you have to be credible when it comes to the economy and security, you have to have a manifesto programme that is credible and speaks about the challenges that the country faces. Those are the things we didn’t do in the most recent general election.”

Asked whether Corbyn’s advisers, Seumas Milne and Karie Murphy, should also go, he said: “Yes I think we need a clean break, we need a new leadership team, a new leader, new people coming into the shadow cabinet, new advisers in the leader’s office: A clean break with the past and a fresh start.”

Jarvis said he had been physically confronted by angry former Labour voters many times during the campaign who did not feel the party represented them any more. He said he wanted to reflect over Christmas on what role he should play in Labour’s future.