Alastair Campbell has repeated his warning that Labour can not win the general election in 2020 by moving further to the left.
During the Labour leadership campaign, Tony Blair's former communications director made no secret of his desire to see Corbyn lose.
Now that Corbyn is in position, Campbell said he did not want to "cause him difficulties". However he told BBC Newsnight that Labour's new leader would struggle to reconcile the wishes of his enthusiastic anti austerity supporters and the country at large.
And he said it was "foolish" of Labour to abandon the election winning strategies adopted by Blair.
"If you are the Labour Party or Tory party, when you pick a leader, this is the person you are saying to the country for the next few years, 'this person should be your prime minister'," he said.
"Ultimately for me it's about whether the Labour Party can reconnect with the public," he said. "There is no evidence that actually, by a substantial shift further to the left, we are going to get any chance of winning another election."
Campbell added: "All these people that have come into the Labour Party expressly to support him and see him as this sire type figure who is going to solve all the problems of the wold and end austerity, is he going to do the things they are expecting at the same time as meeting the desires and needs and aspirations of the British people?"
The New Labour spin doctor also defended Blair's electoral legacy amid calls for the party to learn lessons from Labour's defeats. "We have also got to learn a few lessons about how you win," he said.