SNP "heavies" came close to intimidating broadcasters, Lord Steel of Aikwood, the former Holyrood presiding officer, claimed last night as he bemoaned how Scotland was becoming like a one-party state.

The broadside from the ex-LibDem leader reignited the row over Alex Salmond's non-appearance on a BBC rugby programme. Earlier this month, the First Minister was involved in a spat with the corporation after he was excluded from appearing on its TV broadcast of the Six Nations tie between Scotland and England at Murrayfield.

Mr Salmond decried the decision and described the BBC executive who made it as a "gauleiter". His political opponents accused him of using a Nazi slur.

The corporation said the FM had asked to be included on the programme, but his appearance had never been confirmed and had been refused following two requests for him to appear on radio. However, the Scottish Government accused the BBC of getting its "facts wrong" and pointed to emails showing Mr Salmond had indeed been invited to appear.

During a contribution to the committee stage of the Scotland Bill last night, Lord Steel told peers: "When I switched on my television that Saturday at 4.30 to watch that dreadful Calcutta Cup match, the last thing I wanted to see was the First Minister popping up to give his inexpert views. He should be concentrating on governing the country, not looking for camera calls wherever he can."

The LibDem peer added: "We are being told by some people that to be anti-SNP is to be anti-Scottish. It is time they understood that the rest of us resent being told that to be pro- Scotland, you have to be pro-SNP. That's not the case".

Referring to the TV row, Lord Steel said: "I have been told by other broadcasters that the Salmond rugby experience was not unique for them and that SNP heavies have made more regular calls of complaint to newsrooms than all the other political parties put together and that this is running at times close to intimidation.

"We are seeing a trend towards the attributes of the one-party state, where news bulletins are led by stories of what the dear leader has been doing today and that is a real danger."

Lord Maxton, the Labour peer, interjected, saying the strangest aspect of the BBC row was the claim by the First Minister that somehow the corporation was biased against him. "I would suggest anybody who listens to Good Morning Scotland...would know the exact opposite is the truth," he said.

His Labour colleague, Lord Foulkes, said some people now regarded Mr Salmond as something of a "messiah", who was showered with accolades including from "his best friend", media tycoon Rupert Murdoch, but who was now "melting under the heat of the spotlight" on policy scrutiny.

Earlier, Lord Forsyth, the former Conservative Scottish Secretary, denounced plans to give Scotland the ability to set its own speed limits and drink -rive laws as "plain silly".

He said: "I cannot see why we need to have different speed limits or different rules relating to drink-driving between Scotland and England."

Lord Wallace, the Advocate General, responded by saying differences in speed limits across the country were not "insuperable problems" and suggested Lord Forsyth was trying to make difficulties where none existed.

The most contentious amendments to the Bill, relating to the independence referendum, will be taken during the last day of committee on March 15 after the UK Government's consultation on the issue.

l Labour said the announcement of a referendum in Ireland, expected before the summer, put pressure on the SNP. The Irish people are to be asked to vote on the proposed EU treaty.

Labour's Patricia Ferguson said: "This adds further pressure to the SNP to speed up their plans for a referendum."