Ex-prime ministers Gordon Brown and Tony Blair led tributes to former Labour energy minister Malcolm Wicks who died at 65 on Saturday.
Mr Brown called the Croydon North MP (pictured), who had been fighting cancer, a "great thinker, writer, campaigner and parliamentarian," while Mr Blair said he had "complete integrity in all he did."
Labour leader Ed Miliband praised him as a "thoroughly decent, intelligent and compassionate man" whose death left a "huge hole" in the party.
He added: "He was a brilliant energy minister, he was a deep thinker about welfare and pensions and Labour to his core."
Mr Wicks represented Croydon in Parliament for two decades and held a variety of ministerial briefs under Mr Blair and Mr Brown - including pensions, science and energy.
He was re-elected with an increased majority of nearly 16,500 at the 2010 general election.
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