Labour leadership candidates
The four Labour leadership candidates: (L-R) Jeremy Corbyn, Liz Kendall, Yvette Cooper and Andy Burnham at a hustings event on 20 June 2015. REUTERS/Darren Staples

Latecomer and now surprise frontrunner in the Labour's leadership contest, Jeremy Corbyn has admitted for the first time that he wants to the UK's Prime Minister.

Speaking at the LBC radio station together with the other three Labour candidates, Corbyn, 66, said he did want to be the Labour leader and become Prime Minister.

"Of course, that's why we're here. I want to see this country change," the North Islington MP told the radio station.

At the same event, Andy Burnham, the former favourite to win the leadership contest, said that he would serve under Corbyn should the left wing candidate become the next Labour leader, replacing Ed Miliband who stepped down after the party's worst election defeat in 30 years.

The shadow health secretary said that he would be loyal to whoever emerged as the leader of the party.

"It that was the decision of the Labour Party, I would of course be loyal to the Labour Party and loyal to Jeremy."

The other candidates however did not appear to be so eager. Shadow care secretary Liz Kendall said: "I so fundamentally disagree with Jeremy's approach and I think it would be disastrous for the party and it would be disastrous for the country."

Shadow home secretary Yvette Cooper apparently would only say: "I think it's unlikely," She added that she would not stand for shadow cabinet elections if Corbyn become the Labour leader.

According to the Daily Mail, shadow business secretary Chuka Umunna, who pulled out of the leadership race, has also said that he would not serve under Corbyn.

Former Labour prime minister Tony Blair has warned the party that it would be left out of power for another decade if it moves to the left and votes Corbyn as its new leader.

How will candidates vote for EU referendum?

During the radio show, Ukip leader Nigel Farage called in and asked the Labour candidates whether they would vote No in the UK referendum on EU membership.

Corbyn, when pressed, said he would only vote No "if Europe becomes a totally brutal organisation which treats member states in the way it has treated Greece", then it would lose the support of many people.

Burnham however said there are no circumstances in which he would vote no, saying that this is because he believed "being in Europe is better for jobs in our country."

Liz Kendall said she was a Yes voter "first and last and always. If I thought it wasn't in Britain's interest, I would vote No, but I think it is in Britain's interests."

A recent YouGov survey for the Times has shown that Corbyn is backed by 43% of Labour members, followed by Burnham, the bookies' favourite, on 26%, Cooper on 20% and Kendall with 11%.