The Labour party took Scottish voters for granted and risk doing the same in other parts of the country, Labour's former cultural secretary has warned.
Tessa Jowell told a fringe meeting at the Labour conference, that the referendum campaign had been a "midnight horror" for the party.
She also gave her strongest indication yet that she plans to seek the Labour nomination for London mayor in 2016.
"I always gets nervous when anybody says London is a Labour city," she said.
"We should never ever take it for granted. If we ever needed a midnight horror of what happens when you take your Labour voters for granted it's what just happened in Scotland. Thirty seven per cent of Labour voters voted 'Yes' in Scotland."
Jowell's warning follows a day in which her party sought to claim victory for the referendum campaign in Scotland.
Labour leader Ed Miliband sought to celebrate the party's campaign which saw the 'No' lead all but vanish in the final weeks as Labour voters deserted the party.
Better Together chief Alistair Darling also struck a triumphalist tone accusing departing first minister Alex Salmond of having lost the referendum and "lost the plot."
Jowell said yesterday that she had little choice but to stand for London mayor.
"I think this is the greatest job in the world. It's not what I had planned to do but I think that if you feel there is a job that you can do and you can contribute then you've got to have a very good reason for not doing it."
She also suggested she was the candidate who could appeal beyond party lines, highlighting the fact that both Boris Johnson and Ken Livingstone had won by appealing to large numbers of voters from other parties.
However, she said that it was not the time to formally announce her campaign as her priority was "campaigning with our candidates in marginal seats."
Labour's selection process for their London mayoral candidate will not officially begin until after the general election.
However, two candidates, David Lammy and Christian Wolmar have already launched their campaigns and there has already been a number of unofficial hustings for the potential candidates.
Diane Abbott, Lord Adonis, Margaret Hodge and David Lammy will take part in another fringe debate tonight titled: "London's future: What next for the capital?" Jowell has also been invited.