Donald Dewar led the campaign for a new parliament building in Scotland, the Fraser inquiry has heard.

The inquiry, led by Conservative peer Lord Fraser of Carmyllie, opened on Tuesday and will examine how the costs of the new parliament building spiralled to an estimated £400 million.

Giving evidence on Wednesday former first minister Henry McLeish said that it was Dewar who held key meetings with Cabinet ministers over plans for a new building.

"In your proceedings yesterday Brian Wilson [former Scotland Office minister] made the point that Donald Dewar was the custodian of the project," said McLeish.

"That's perfectly understandable because there were a lot of important considerations for Donald, for Scotland and for the wider UK.

"He did take an enormous interest in that so therefore I think that's more inevitable than a basis for criticism."

Dewar, who became first minister immediately after devolution, "pitted himself against the biggest beast at Westminster" to get his own way on the arrangements for the new Holyrood parliament, Lord Fraser heard.

McLeish defended the decision not to renovate an existing building, even though the Royal High School in Edinburgh's Calton Hill area had once been a favoured location.

"I always had the view that the Royal High School on its own could never be a long-term basis for the Scottish parliament," he said.

A debating chamber in that building would have been adequate but the grounds were "wholly unsuited", he added.

"I put on record that I disliked the building as a functional parliament building the first time I ever stepped within it."

But McLeish claimed that as a Scottish Office minister in Westminster, his focus remained on the devolution white paper.

"It was my view that there was no issue more important than the white paper and as a consequence of that I regarded everything else linked to devolution at that moment in time as less significant," he said.

However, he added the then-Scottish secretary dominated issues in this area, too.

"Donald Dewar had to know every detail and I would say that as a consequence, and I could stand corrected by later evidence, that I was not involved nor were any others in the detail of the white paper to the extent you might think," McLeish argued.