Mr Miliband has been touted as a future Labour leader
The Labour Party needs to change the way it is organised, Foreign Secretary David Miliband has said.
In a speech to commemorate former Labour leader John Smith, Mr Miliband argued there was a "real and pressing" need for organisational renewal.
Mr Miliband added Labour now needed to be a different kind of party because traditional politics was "dying".
But he also acknowledged that some policy areas had not seen the change that some expected from New Labour.
'Failed to deliver'
In his speech, the foreign secretary called for greater involvement of trade unionists in party structures and said Labour should give some of its income to charity to give an example of corporate responsibility.
He also praised the ability of the Obama campaign to involve so many individuals in his campaign and cites favourably open primaries - something favoured by David Cameron - to elect local politicians.
Mr Miliband said Labour needed to be different, not "in its decency and diligence, but different in its structures and role" because "the traditional political structures of mainstream political parties are dying".
He added: "Shrinking membership, declining affinity, fuzzy identity lead many to proclaim that death has already happened, with few tears at the funeral."
Appraising Labour's record in office, Mr Miliband said transport had not "fundamentally changed", a shift in power from Whitehall to local government "has not yet happened" and, on the environment, "our low carbon revolution is still to come".
He added: "The charge against the Labour gvernment after 12 years is no that we've had too much change, but that we've had too little.
"People wanted in some ways a revolution - or at least disruptive changes of course - and that we have failed to deliver it."
Concluding his speech, Mr Miliband said: "As we face the massive challenge of seeking a fourth election victory, we miss John Smith.
"We honour his decency, his calmness, his eye for the devastating attack. But we go forward stronger for his example."
Mr Miliband's speech echoes his comments on Sunday's Andrew Marr show, when he said Labour must reinvent itself for the 21st Century.
BBC political correspondent Gary O'Donoghue said some will regard that as an implicit criticism of Gordon Brown and his style of leadership, and will see Mr Miliband's foray into the debate over Labour's future as a sign that the foreign secretary has not given up any leadership ambitions.