The government has been seriously worried about the level of support for the Scottish National Party for many months.

Last week's European by-election in the seat of North East Scotland saw Labour come third behind the Tories.

A speech by the Scottish Secretary Donald Dewar on Monday is expected to offer potential supporters of the Scottish National Party.

But he has denied the party will change its approach and that it is his duty to stop those who want to challenge the basis of the United Kingdom.

Labour were beaten into third place in a biyelection

One theory about the party's loss of support since the general election is that voters want their assembly to have more power, with fewer policy areas controlled from London.

Ian Davidson, one MP who has failed to secure his party's nomination to run for the Scottish Parliament, believes Labour needs to change tack.

He told BBC Radio 4's The World At One: "I hope the result forces a rethink because the aggressive rebuttal strategy we picked up from Millbank is alienating a lot of Scottish opinion."

The party is desperately in need of a change in approach, Mr Davidson said.

He added: "We seem to be saying the world is flat and unless you vote Labour you will fall off the edge.

"We seem to be trying to panic people by point out the SNP are horrendous, the result of independence would be appalling and all the rest of it.

"Much of that comes across as simply anti-Scottish. We're presenting ourselves pretty as much as the Tories did before the general election and look what happened to them."

Hence the rumours that Mr Dewar might be ready to adjust the terms of the Scotland Act before next May's election.

Malcolm Chisholm, the former Scottish Office minister who is likely to be in a new Holyrood Parliament, is also slightly concerned

He said: "We need to have a stronger positive message and we need to perhaps change our tone slightly of our criticisms of the SNP."

Donald Dewar: No question of changing tack

Mr Dewar told The World At One that his speech would be a positive one but there would be no question of changing direction.

He said: "Within the Scotland Act there is machinery for adjustments.

Donald Dewar talking to Radio 4's World At One programme: No major changes

"Those will be adjustments where there is some common consent where we need to tidy up some of the detail of the settlement."

But Mr Dewar refused to allow those who wanted a "right angle change to take Scotland out of the United Kingdom".