LORD Smith, who chaired the cross-party commission on devolution following last year's independence referendum, has criticised MSPs for failing to hold ministers to account.

In an interview with a Sunday paper, he said Holyrood did not provide the same level of scrutiny as Westminster.

He said: "You watch the way the scrutiny works in Westminster.

"It is vicious sometimes. I've appeared before a couple of select committees. They are unafraid to challenge. They are knowledgeable.

"We don't have that at Holyrood."

He added: "There needs to be better scrutiny.

"The Commons select committees take their own MPs and beat them around, and rightly so.

"It doesn't happen here. I don't know why. It hasn't properly been built into the system.

"But nobody should be afraid of that. You need challenge.

"If I was the Presiding Officer I would haul in the leaders of the parties and say something has to change."

The SNP has been repeatedly accused of 'politicising' Holyrood's committee system and using its majority to block inquiries which might embarrass ministers.

Presiding Officer Tricia Marwick suggested conveners should be directly elected by MSPs, rather than picked by party leaders, in a bid to make them more impartial.

However, MSPs rejected the idea.