Meetings between senior politicians from the UK's devolved administrations "didn't really do very much" a former Scottish deputy first minister said, as he recalled Tony Blair "looking out of the window" while he chaired one of the high-level sessions.

Lord Wallace said he recalled there being just three of the meetings, which bring together ministers from different parts of the UK, over the six years he was deputy first minister at Holyrood.

The Liberal Democrat, who is now Advocate General for Scotland, was questioned about the use of such talks as he gave evidence to the House of Lords Constitution Committee on intergovernmental relations in the UK.

Baroness Dean of Thornton-le-Fylde said concerns had been raised that the JMCs, which bring together senior politicians from the UK's devolved administrations, had been used for "grandstanding" and as a "place for airing grievances but not necessarily for resolving them".

Lord Wallace, who was the deputy first minister at Holyrood from 1999 to 2005, said he had not been at one of the plenary sessions - which are usually chaired by the prime minister - in recent times.

He said: "I last attended a JMC plenary was when I was a deputy first minister. I seem to recall we had three. The first one in Edinburgh was novel and everyone was quite excited by it. The second one in Cardiff was less exciting, and the third one, which we had in Number 10, my recollection is prime minister Blair looking out the window and we never had another one."

But he added that neither he nor Lord McConnell, the Scottish first minister at the time, were "particularly aggrieved" by this as it "freed-up time in the diary".

Lord Wallace said: "They didn't really do very much."

Scottish Secretary Alistair Carmichael said the briefing he had been given by officials "says that joint ministerial committees have been and are productive and useful".

But he added: "When I hear talk of grandstanding I can identify elements that I could readily identify as justifying that tag. They occasionally generate a bit more heat than light.

"But let's not forget when you take a room, fill it with politicians from different parts of the country, from different parties, and leave the press at the door, yes, you're going to get a bit a bit of politics happening. That's how it works."

He argued that under the current devolved system there "is need for a structure that allows formal meeting and discussion and sharing of experience" between politicians from different administrations.

The UK Government minister added: "You have to be realistic about your expectations of exactly how much that will achieve. Ultimately the best structure in the world will work as well or as badly as the politicians who are part of it want it to work.

"If you don't have that willingness, and candidly there were times in the last few years when there was not that willingness to make it work, then ultimately it doesn't work as well as it should."

This report of proceedings replaces an earlier version in this online article, which erroneously misquoted Lord Wallace.