A referendum on the UK’s constitution should be a “one-off generational thing” which cannot be re-run for up to 20 years, a former Labour first minister has said.

Lord McConnell said while it was “inevitable” that there would be a referendum on Scottish independence, the SNP must “get back to basics” after losing that ballot in 2014.

He said: “I’m not in favour of re-running referenda every few years, or even possibly within 15, 20 years.

“I think if you lose a referendum you have to get back to basics, and build up your case and fight another day, but recognise that that day is going to be a long way off.”

He was speaking just hours before an expected statement by current First Minister Nicola Sturgeon on Scotland’s future in the wake of Brexit.

Lord McConnell said the 2016 referendum on the UK’s membership of the European Union “was not necessarily a bad thing in principle”, but it had been “handled appallingly badly” by then prime minister David Cameron.

And while he said he did not enjoy the referendum in 2014, “I don’t think it was necessarily wrong that at some point we had to make a choice on that”.

Speaking at an event in Edinburgh organised by the think tank Reform Scotland, the former first minister said: “What I don’t like is the idea that we keep having them.

“To me a referendum is a one-off generational thing and those who lose, no matter what the circumstances really, unless they are really really extreme circumstances, I think you have to accept the result.”

Lord McConnell
Lord McConnell said referendums on the UK’s constitution should not be repeated quickly (PA)

He also warned Labour politicians that a vote for independence in Scotland would not necessarily return his party to power north of the border.

He told the event, held to mark the 20th anniversary of the creation of the Scottish Parliament, Lord McConnell said: “I think the political outcome of an independent Scotland would depend a lot on the economic circumstances of the time.

“If, as I think is now even perhaps anticipated by some of those who support independence, the early years of independence were a bit rough, people in Scotland would probably look for strong leadership, I’m not sure it would necessarily matter what party that was coming from.

“So a lot would depend on the leadership of the SNP, Labour the Conservatives, those three parties.

“I think those who assume that an independent Scotland would automatically be a Labour Scotland, I don’t think that is a correct assumption at all. We are in far too volatile political times for that to be assumed.”