Gordon Brown has revealed he is finding the job of fighting to keep Scotland in the union more enjoyable than his time at 10 Downing Street.
He joked that the press had been a lot kinder to him since he stepped out of the shadows to campaign against independence.
The Labour MP said he quit frontline politics after he lost the 2010 general election but said he had become involved in the referendum because of the impact separation could have on future generations.
Asked how the challenge of the campaign compared to his time as prime minister, Mr Brown, who has two young sons Fraser and John, quipped: “Well I am enjoying this campaign and the press has been a lot kinder to me.”
Turning on a more serious note, he said: “This is about my children and my children’s children.
“Anyone who is a parent who is entering this campaign knows that this is not similar to a general election vote or similar to an ordinary vote in a council election or a European election.
“This is about the long-term future and it is an irreversible decision, so the votes we are casting are not just for ourselves or even our communities today, these are also being cast for our children and our children’s children.
“Everybody knows if the decision went one way it would be irreversible and it would mean our children would be affected by something we had decided. That’s why I’m involved.”
Pro-UK campaign group Better Together commissioned a poll that showed the vast majority of Scots thought North Sea oil wealth should benefit people across the UK.
Mr Brown, a former chancellor, dismissed SNP proposals for a oil fund in the event of a “yes” vote.
He said the oil revenues forecast for 2016-17 was £3.2billion while Scotland’s pension bill will be £9billion, £22billion for social security, £8billion for education and £11billion for health.
Mr Brown said: “So whatever else the oil revenues can deliver it is only a fraction of the cost of the services we guarantee as part of the UK
“The idea that we are going to benefit a huge amount from now setting up an oil fund is in my view testified by these figures.
“As for the past, you cannot relive the past and there were very good reasons at the time for not having a oil fund.”