Gordon Brown has thrown his weight behind Sir Keir Starmer's bid for the Labour leadership, saying he has the qualifications to be "a prime minister of the future".
The ex-premier stressed the need for Labour to unite and said there were "three worthy candidates" to replace Jeremy Corbyn.
Cherie Blair, wife of newly elected Labour Party leader, Tony Blair, celebrates with former leader, Neil Kinnock, and Gordon Brown at the Institute of Education.
The new Shadow Cabinet in the Shadow Cabinet Room at the House of Commons.
From left, Back row: Michael Meacher, Dr David Clarke, Donald Dewar, Bryan Gould, Barry Jones, Tony Blair and Frank Dobson.
Front: Dr John Cunningham, Derek Foster, Jo Richardson, Stan Orme, Gerald Kaufman, Neil Kinnock, Roy Hattersley, Robin Cook, John Prescott, Gordon Brown and Jack Straw.
Labour leader Neil Kinnock with his economic team in London, where the Shadow Cabinet was meeting.
Shadow Home Secretary and Labour Leadership front runner Tony Blair confers with Shadow Chancellor Gordon Brown outside the House of Commons.
Labour Party leader Tony Blair (R) and deputy leader Gordon Brown during a preview of Labour's pre-budget party political broadcast at Church House, Westminster, London.
Labour leader Tony Blair, flanked by Gordon Brown (left) and deputy leader John Prescott, unveils the party's plans to prepare for a general election, during a news conference by the National Executive Committee, in London.
Chancellor of the Exchequer Gordon Brown meets Pain (a character from the film Hercules) when Mr Brown hosted a Christmas party to benefit SCOPE at No.11 Downing Street this evening.
Chancellor of the Exchequer and Chairman of the Committee for the Diana, Princess of Wales Memorial Fund, Gordon Brown and Diana's sister, Lady Sarah McCorquodale, speak to the media outside No. 11 Downing Street today (Monday) following the first meeting of the committee this afternoon. Watch for PA Story.
(l/r) British Prime Minister Tony Blair, Deputy Labour Party leader John Prescott and Chancellor of the Exchequer Gordon Brown listen intently to David Obaje speaking on the platform at the Labour Party Conference at the Winter Garden conference Centre in Blackpool this morning.
Prime Minister Tony Blair (L) and Chancellor of the Exchequer Gordon Brown, during the Nicky Campbell Show, a live phone-in programme at the BBC Radio 5 Live studios in Central London.
File photo of Prime Minister Tony Blair (left) and Chancellor Gordon Brown sampling a cup of coffee at the Starbucks Coffee Bar in Villers Street, central London, dated 10/11/99.
Chancellor Gordon Brown, 49, and his wife, PR executive Sarah Macaulay, 36, after their wedding in a small private ceremony held at his home in North Queensferry, Fife. The couple enjoyed a 6 year courtship before their wedding.
Britain's Prime Minister Tony Blair flanked by Chancellor Gordon Brown (right) and Education Secretary David Blunkett sit in a first class coach on to a Virgin service at London's Euston Station for the one-and-a-half-hour trip to Birmingham, for the party's manifesto launch.
Britain's Prime Minister Tony Blair (left) and Chancellor of the Exchequer Gordon Brown on the Labour "battle bus" on the way to Harlow, Essex, where Mr Blair appealed to mainstream Conservatives to back the Labour Party in the General Election.
Prime Minister Tony Blair (left) and Chancellor Gordon Brown during a pre-election visit to a fish and chip shop in Harrow, north London.
Chancellor of the Exchequer Gordon Brown is given a cup of coffee by his wife Sarah in his Downing Street apartment as he prepares to deliver his 2002 budget later. Brown is expected to announce an increase in National Insurance contributions. *... to help pay for the rejuvenation of the National Health Service.
Prime Minister Tony Blair, The Chancellor of the Exchequer Gordon Brown (left) and Health Secretary Alan Milburn (right) in the House of Commons during Prime Ministers' Questions in London. * Downing Street said today that Mr Blair remained "confident that a second United Nations resolution paving the way for war with Iraq would be carried. The comments came after Mr Blair held 50 minutes of talks in No 10 with Russian foreign minister Igor Ivanov this morning.
The Chancellor of the Exchequer Gordon Brown leaves Number 11 Downing Street to present his seventh Budget to the House of Commons, central London.
The Chancellor Gordon Brown (centre right) holds a torch lit in Athens as it arrives in London's Parliament Square on its way to Glasgow and then Dublin, for the Special Olympics World Summer Games which are being held in the city from 21 June.
Chancellor Gordon Brown chats to players before starting the charity football matches taking place in Victoria Tower Gardens, central London to raise money for the charity Piggy Bank Kids, which was started by Brown and his wife Sarah.
Chancellor Gordon Brown, 52, holds his son John as he stands with his wife Sarah, 38, at the Edinburgh Royal Infirmary. The Chancellor's newborn son, John Brown was born on Friday 17th October 2003. The new parents were beaming with joy as they posed for photographs before heading off to their home in North Queensferry.
Rt Hon Gordon Brown MP with tv presenter Fiona Phillips during the ePolitix Charity Champion Awards at the QE2 Conference Centre in Westminster, central London. Gordon received the Children and Youth Champion Award at the ceremony which pays tribute to the hard work and time key parliamentarians devote to charitable causes and capaigns in Parliament.
Chancellor Gordon Brown chats with Radio One DJ Sara Cox, at 11 Downing Street, during a Christmas party the Chancellor hosted for the children's cancer and leukaemia charity, CLIC, which over two decades has been transformed into one of Britains most dynamic children's charities, offering help and support to a growing number of families across the UK.
Gordon Brown, Chancellor of the Exchequer is presented with a shirt from Charlton Athletic's Manager Alan Curbishley
Chancellor Gordon Brown (left) stands with Dr Alan Greenspan, Chairman of the US Federal Reserve.
Sir Bob Geldof (right) and British Chancellor Gordon Brown at the British Museum in central London, where they met members of the Africa Children's Choir, who were there as part of Africa Live - a venture between the museum and the BBC.
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He praised Rebecca Long-Bailey for stressing the importance of a "green new deal" and Lisa Nandy for talking about "empowering our communities".
"But there is one candidate with the expertise, with the eloquence, with the dedication, with the commitment and indeed with the values that are necessary for Labour to return to power," Mr Brown said.
"Keir Starmer has all the qualifications that are necessary for a Prime Minister of the future.
"A vote for Keir Starmer is a vote for hope. It's a vote for the future. It's a vote for the values that all of us believe in deeply. Join Keir Starmer and let's elect a Labour Government."
Mr Brown said 10 years of Tory rule had "succeeded in demolishing much of the social fabric" of the country, with public services deteriorating and an NHS "struggling from crisis to crisis".
"Britain deserves better than this and it needs a Labour Party with a vision of what can be achieved in the new world of the 2020s," the former prime minister said.
"When Labour has come together and been united we have had massive achievements that have changed the face of Britain."