Elaine C Smith, the actress, waded into the row over Scotland's constitutional reform yesterday by accusing David Cairns, the Scotland Office Minister, of failing to "keep pace" with the country's wishes.

The actress's intervention came as the chairman of Labour's Scottish MPs pleaded for party officials north and south of the border to stop squabbling and instead form a united front against the SNP.

In an interview with The Herald earlier this week, Mr Cairns, the MP for Inverclyde, had said there was "no case" for substantial changes to Holyrood's fiscal powers and said talk of devolving new powers was an issue for the "McChattering classes".

Leaders of the Scottish Independence Convention - an umbrella group for those supporting independence - have now called on Mr Cairns to apologise for his remarks.

Smith, the group's convener, said: "Mr Cairns has voiced his disapproval at our call for a referendum, he wants it to go away. He seems to believe if we don't talk about it, it won't happen. But he fails to realise the Scottish people have moved on. It is he who has failed to keep pace."

Labour MPs, MSPs and councillors are preparing to meet today to plot the way forward in the wake of their defeat in last year's Holyrood elections. Ann McKechin, the MP for Glasgow Maryhill, acknowledged that the past week, which has seen senior Labour figures at Holyrood and Westminster briefing against one another, had been "uncomfortable" for the party.

However, she said today's meeting in Glasgow was an opportunity for the party to decide how best to cope with the new "political environment" in Scotland.

She said: "At Westminster, we need to be supporting our colleagues at Holyrood in terms of their opposition to the SNP much more fully than we previously needed to do."

The root of the discord between Labour at Holyrood and Westminster has been Scottish leader Wendy Alexander's decision to set up a Constitutional Commission to look at whether or not the Scottish Parliament should have more powers, particularly greater fiscal autonomy.

Ms McKechin yesterday acknowledged there had been a "frank" exchange of views when Wendy Alexander met MPs in London last week, but insisted her group were willing to give the idea a fair wind.

She said: "Clearly we will have different views and we don't have a formed view about what reforms should take place, but we're prepared to take part in an active dialogue. The majority of members in the Westminster group feel it needs to be based on hard evidence and of clear benefit to the electorate."

The SNP, meanwhile, yesterday sought to exploit the apparent split in the Labour ranks. Alasdair Allan, the Nationalist MSP for the Western Isles, said: "If Wendy Alexander is to lead the Labour Party in Scotland she needs the backing of the party across the country and in both parliaments.

"It is clear she does not have that."