ALEX Salmond has claimed a hung parliament at the General Election would offer a strong cohort of nationalist MPs the opportunity to "rumble up" Westminster and deliver "real power for Scotland", as he set out his party's battle lines ahead of next May's vote.

The former First Minister predicted that it was likely that there would be no overall majority for Labour or the Conservatives following the election and that the SNP may well become the third-largest party in the UK, a scenario he said would put the nationalists in a "very strong position".

Labour responded by saying a vote for the SNP would be a vote to let David Cameron back into Downing Street while the Scottish Conservatives criticised Mr Salmond for "desperately wooing the parliament he failed to destroy".

However, following confirmation that Mr Salmond would stand in the Gordon constituency, bookmakers William Hill offered odds of 6/1 that the MSP would go on to become a minister in the next UK Government, and 13/2 that the SNP would form part of a coalition.

Professor John Curtice, a polling expert, said that the strategy laid out by Mr Salmond was "completely realistic" with the most recent surveys suggesting the party could win upwards of 40 seats.

Mr Salmond said that the SNP and its "progressive allies" had moved into a "commanding position in Scottish politics", and appeared to attempt to cast himself as the successor to Gordon Brown as the self-styled "guarantor" of more powers for Holyrood following the former Prime Minister's announcement that he is standing down as an MP.

"Politics is never certain but there does seem the be a reasonable prospect of a hung parliament and certainly, the Scottish National Party will have a lot more MPs than Ukip will, we may have more than the Liberal Democrats," Mr Salmond said.

"Nicola Sturgeon has already laid out what our parameters are - we will not deal with the Tory Party in any shape or form, they are not trusted in Scotland. But there are a number of other permutations and if we have that strong group of MPs then we can secure what Scotland was offered in the referendum campaign and, indeed, we can strike a blow for progressive politics across these islands."

He warned that the "bleak" prospect of further austerity and a "continued assault on the poor" was a prospect unless the SNP had influence at Westminster and added: "A strong group of SNP MPs will have the capacity to rumble up Westminster. As I recall we managed to rumble up Westminster with a small group of SNP MPs, so we should manage to do it with a large group."

Meanwhile, a fresh poll suggested that Scottish voters believe the Tories were likely to win the most seats UK-wide in May, reversing a long-term trend in which Labour had been seen as being ahead.

Professor Curtice, of the University of Strathclyde, said Mr Salmond's analysis was backed up by the polls, with Labour seats set to "fall like ninepins" if the nationalists maintain their lead.

He added: "What's going on is that people are still focused on what's best for Scotland, they have not been thinking about the British process for the last two years. If people are focused on what's best for Scotland, they tend to vote SNP. Labour need to try and drag people back to asking 'who is going to be best to govern Britain?' But the Tories have been putting a similar argument to the UKIP supporters in England and it's gone nowhere.

"It remains to be seen whether the SNP will have enough seats to put someone over the line [in terms of a majority]. One of the things they have done is to say they won't do a deal with the Tories. That will weaken their bargaining position as Labour will know they are the only game in town."

A spokesman for Labour said that the General Election represented a clear choice between Labour and the Tories, and that 'the vow' of more powers for Scotland had already been delivered.

He added: "What people across Scotland want now is a Government that gets to grips with the cost-of-living crisis and secures the recovery.??