OWEN Smith, the relatively unknown MP for Pontypridd, has insisted Labour needs a “new generation” of leader as he became the sole challenger to Jeremy Corbyn for the Labour crown after Angela Eagle pulled out.

The former shadow business secretary withdrew “in the interests of the party” after she received fewer nominations from MPs and MEPs than her Welsh colleague.

Hours earlier, they had come to a private arrangement that whoever received fewer nominations would withdraw and support the other as the “unity candidate”.

Opponents of Mr Corbyn believe that a single challenger will have a far better chance of defeating the Islington MP in a straight head to head; although a new poll has suggested that whoever ran against the incumbent would lose.

Bookmakers have placed Mr Corbyn as the odds-on favourite to repeat his victory of last September.

It emerged that Ms Eagle, 55, the MP for Wallasey on Merseyside, had received 72 nominations from MPs and MEPs, 18 fewer than Mr Smith’s 90.

Announcing her withdrawal, she immediately made clear she would back Mr Smith "with all her might and enthusiasm".

Ms Eagle also made a heartfelt appeal for people to pay the £25 to register to take part in the leadership race before the deadline of 5pm Wednesday.

Following her decision to withdraw, Mr Smith, described his colleague as a “star in the Labour firmament” and said if he won the Labour crown, she would be “alongside me as my right-hand woman".

Labour sources noted how Mr Owen not only had the advantage of being a better media performer than Ms Eagle but also had “no baggage”; that being a relatively unknown MP – he entered parliament in 2010 – would be an advantage in presenting himself as a new generation of leader compared to the 67-year-old incumbent. Ms Eagle served in Gordon Brown’s government and backed the Iraq War in 2003.

Hustings will now take place with the final result announced on September 24, on the eve of the party conference.

Mr Smith, 46, a former shadow work and pensions secretary, said: “I want to say to all members of the Labour Party tonight, young and old, long-standing and new members: I can be there champion; I am just as radical as Jeremy Corbyn.

“We do need a new generation of Labour men and women to take this party forward, to get us ready for government once more. We’ve been on the sidelines for too long.”

He paid tribute to Mr Corbyn for helping Labour rediscover its roots but made clear it was now time for the party to be "credible" in the eyes of ordinary voters again.

"The Tories are destroying many of the things that Labour built over decades; they’re being dismantled piece by piece and Labour cannot stand by on the sidelines and let that happen.

"We have got to fight for our values and to do that we’ve got to be powerful in this place, powerful in our communities and credible. The country has to look at us and say: ‘We can imagine these people running this country and doing so better than the Conservatives.’

“That’s the task I’m setting myself, that’s the task I’m setting everybody in Labour and I expect us to achieve it,” he added.

Mr Smith was born in Lancashire but raised in Barry in the Vale of Glamorgan. The son of a Welsh historian, he was state educated and studied French and History at Sussex University.

A former BBC radio producer, he was a special advisor to former Welsh secretary Paul Murphy. He worked as a lobbyist for pharmaceutical companies before entering parliament six years ago.

Regarded as being on the “soft Left,” he became shadow Welsh secretary under Ed Miliband’s leadership and was promoted to the work and pensions brief under Mr Corbyn. But, like Ms Eagle, he resigned his role following the EU referendum result.

A former CND supporter, he now supports retention of the nuclear deterrent. He opposed military intervention in Syria and was in favour of Britain staying in the EU. He supports holding a second referendum on the final Brexit deal.