Video report by ITV News presenter Julie Etchingham
Speaking to ITV News Presenter Julie Etchingham, the Labour veteran tackled Scottish independence, the future of the Union and shared what he thinks should happen to the country's first minister.
In a wide-ranging interview, Mr Brown accused Alex Salmond and Nicola Sturgeon of "bringing the country down" with their "feud".
He said: "It used to be the case that if you were accused, and there was evidence - you resigned.
"Now, it seems to be the case that if you're accused, you simply say that you're not going to resign and you're not going to take the punishment that's necessary."
Watch the interview in full:
Julie asked if Nicola Sturgeon is found to have broken the ministerial code of conduct, would she have to go?
Mr Brown said: "Well, if people haven't told the truth - and that's got to be proven - if people are guilty of bad behaviour, which is proven, as has happened in very recent instances where the prime minister chose not to act...
"If we cannot uphold the highest standards of integrity and if we cannot... take seriously, the vows we make when we go into office, then I think 'anything goes' and it becomes anarchy."
On Scottish Independence, Mr Brown believes now is not the time for a second referendum, and hinted that Labour will be supporting the Union, albeit with plans for a shake-up.
He told ITV News: "Should you have a referendum at a time when we need time to heal from the virus and the recession?
"We also need a time to reflect, we don't have the facts before us yet.
"We don't know what independence means for jobs, for trade, for security, for defence, for the welfare state, for our pensions - nobody has given us these up-to-date facts. And nobody has given us the facts about what it means to stay in the union.
Mr Brown shared his proposals of a reformed United Kingdom: "I want the House of Lords to become a Senate of the nations and regions, or at least we should discuss that.
"I want a forum of the nations and regions, so we look collaboratively at North Wales, Northern Ireland, the Midlands, Yorkshire, at all issues, instead of just the centralising government we have. I want the central government to be more inclusive."
The former prime minister hinted that an alternative, Labour proposal for the future of the United Kingdom would be "on the agenda soon".
He added: "It will be about building better relationships between the regions and nations and the centre of the United Kingdom.
"It will be about greater inclusivity at the centre so that every voice is heard at the centre.
"I believe that that is more likely to command the support of the Scottish people in a referendum, then a proposal for either independence or simply an unchanged status quo.
"So I see things changing over the next year."
With his battle plan for the Union in place, Julie asked if he is "getting ready for a return to frontline politics?"
"No", he said, "I'm not interested in returning to frontline politics either in the House of Commons or in the Scottish parliament. I think when you've done your time, you've done your time.
"But of course... I want Scotland to play a leading role in the United Kingdom in the future, and I will do everything I can to make that happen."
So if party leader Sir Keir Starmer were to ask him to lead Labour's efforts on Scotland, would he?
"I don't think it's something that will be decided either by Keir Starmer or Boris Johnson", he said.
"I think it's really what the Scottish people want.
"If they want a campaign that defends the Union and Scotland's role in it - and a positive proposal for the future of the United Kingdom - I'm very happy to play my part."
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