Lord Mandelson has said he would like to be seen as a "respected grandee or great uncle" whose advice is taken seriously by Labour leader Ed Miliband.
The former business secretary admitted in an interview with Total Politics magazine he was still coming to terms with life outside government.
He said he wanted to maintain an influential role within Labour, and would be "loyal" to Mr Miliband.
"I want to pass on my experience and my wisdom - not to interfere", he added.
Lord Mandelson - who along with former prime ministers Gordon Brown and Tony Blair played an integral role in turning around Labour's electoral fortunes in the 1990s - said: "I want to offer counsel to the new generation of Labour leaders and activists."
'Trusted and respected'
He said his aim was "not to interfere, not to try to rock the boat or drive the car from the backseat.
"Having come back (to domestic politics in 2008 after serving as EU trade commissioner) as a safe pair of hands, I want to continue as such... I want to be trusted and respected for what I am and what I say, not regarded as somebody who just can't bear to move on."
Lord Mandelson - who was brought back into Westminster politics by Mr Brown - has adopted a much lower public profile since Labour's general election loss, sparking suggestions of a rift with new party leader Mr Miliband.
When asked in June whether he would invite Lord Mandelson to join his frontbench team were he to win the leadership race, Mr Miliband said: "All of us believe in dignity in retirement."
In the interview with Total Politics - to be published on Monday - Lord Mandelson said he had felt "denigrated" by Mr Miliband's remarks and disagreed with his party leader's strategy.
"I felt hurt, I felt denigrated by some of Ed Miliband's remarks. Talking about me in terms of 'dignity in retirement', I felt as if I was being unfairly treated and packed off rather prematurely to an old folk's home.
"I also thought to define himself against New Labour, as opposed to being a development of New Labour, was electorally unwise."
And while not ruling out a return to politics, he said he was not going to "sit by the telephone".
But Lord Mandelson was quick to point out: "What's happened since the election is that we've all made up now... we've all moved on. What I've got to do now is remain a candid friend but also constructive and always loyal. I was always loyal."
As for Labour's general election defeat, Lord Mandelson said: "I know I should say to you that I've adjusted, I've moved on, I'm happy, I'm looking forward to the future with confidence.
"But the truth is that I feel a sense of bereavement for our government. Personally, I feel like a rather displaced individual and I'm not coping perfectly."