London mayor Sadiq Khan has told the Labour party conference that while the leadership contest is over, the party must now seek power.
Speaking in Liverpool, Khan listed achievements of Labour administrations, including his own in London, and argued the party's failure to achieve better results was allowing numbers of affordable homes built to to fall, and the numbers of homeless to rise.
The message represented a coded warning to the party's left from Khan, who backed Owen Smith's campaign to oust Jeremy Corbyn as Labour leader.
As London mayor, Khan is the party's most senior elected official, and describing Labour in power, he said it was: "Not just talking the talk, but walking the walk, too. Never sacrificing or selling out on our ideals, but putting them in action every single day.
"Not a revolution overnight, but real and meaningful change that makes life easier for the people who need it most."
He said that Labour out of power "will never be good enough".
"When Labour is not in power, we fail the very people who need us most," Khan said, adding "It's our duty and our responsibility to put Labour back in power across Britain. We have to start by winning the mayoral elections next year in Liverpool, Manchester and Birmingham, and ensuring Labour is in power in every great city in Britain."
Khan's comments come as polling figures suggest the Conservatives are on track for a majority of more than 70 seats in a general election.