British Chancellor Gordon Brown has accepted his nomination for the Labour leadership, saying he was "truly humbled" by the level of support from his parliamentary colleagues.
Mr Brown was confirmed as leader-in-waiting on Thursday afternoon when the party confirmed he was the only contender to make the ballot paper, with 313 MPs' nominations.
"I formally accept the nomination, the responsibility it brings and the opportunity to serve the people of Britain," he told a gathering in London.
"As a teenager, I chose this party because of its values - values I grew up with and knew.
"I am honoured that this party has chosen me."
Mr Brown said that the scale of his nomination, which attracted the signatures of 313 of Labour's 353 eligible MPs "shows to the country a party wholly united in its determination not to retreat into the past, but going forward as New Labour to address the opportunities and challenges of the future".
Mr Brown said he was "conscious that there is no higher calling than to lead and to serve your country".
He said his 10 years in Government had taught him that the best preparation for the development of policy was not meetings in Whitehall departments but "listening to the British people".
When drawing up his agenda for the Queen's Speech, he would be "listening and learning and involving and engaging the voices of people too often left unheard", he said.
He promised "to those who feel that the political system doesn't listen and doesn't care, to those who somehow feel powerless and have lost faith, to those who feel Westminster is a distant place and politics all too often a spectator sport".
"I will strive to earn your trust - to earn your trust not just in foreign policy, but in our schools and our hospitals and our public services and to respond to your concerns."