Former First Minister Alex Salmond will end months of speculation and open a new chapter of his political career when he announces on Sunday that he is standing for Westminster at next year's general election.

Salmond, who had hinted heavily that he will seek a return to the House of Commons, is expected to confirm that he is to contest the Gordon seat in the north-east as an MP. He already represents much of the area as an MSP.

One of Salmond's closest aides told the Sunday Herald: "At our last constituency meeting over 100 local people turned up in New Deer and unanimously asked him to stand. We fully expect a positive answer in Ellon on Sunday."

Salmond stood down as an MP in 2010 but he has spent most of his political career at Westminster. He was an MP for over 20 years between 1987 and 2010 and has served at Holyrood for around nine years.

However, the highlight of his political career was becoming First Minister in 2007 and leading his party to a landslide victory four years later.

Although he fulfilled his ambition of giving the people of Scotland a constitutional referendum, he fell short of his ultimate goal of independence.

He resigned as First Minister after Scotland voted No in the referendum, paving the way for his deputy Nicola Sturgeon to succeed him.

Within weeks of his resignation, he told BBC's Question Time programme that the door was not closed on a return to Westminster.

The Salmond constituency aide said: "Alex can win this seat for the SNP, given that he already represents the greater part of it in the Scottish Parliament.

"His candidature will be a strong sign that the SNP intend to contest the Westminster elections to win, with a view to enforcing the vows made to the Scottish people in the referendum.

"There is great excitement that Gordon will be seen as a key seat in ensuring that Scotland makes progress and that the Westminster parties are not allowed to renege on their commitments to Scotland.

"There is no-one better able to rumble up Westminster and enforce the vow than Alex Salmond."

It is understood Salmond will be a key part of the SNP strategy to win next year's general election in Scotland.

If elected, is it is believed he will help put pressure on the UK Government to transfer more powers to Holyrood than was offered by the cross-party Smith Commission.

Opinion polls show the Nationalists winning a majority of seats and defeating Labour.

A recent YouGov poll, based on a sample of 1103 people living in Scotland, had the SNP leading Labour by 46% to 26%. The Liberals trailed on 6%.

The Gordon seat Salmond will contest next year is broadly similar to the Aberdeenshire East constituency he represents at Holyrood.

The Liberal Democrats won Gordon in 2010 with a majority of 6,748, but sitting MP Sir Malcolm Bruce is standing down.

His replacement is journalist and lecturer Christine Jardine.

In 2007, Salmond overturned a 4071 LibDem majority in the north-east constituency.

Jardine said: "People in the North East are counting the cost of seven years of Alex Salmond. We have been short changed by millions of pounds in council funding, our roads have been neglected and our NHS has been left at breaking point. While Alex Salmond's mind was on his independence crusade, doctors, nurses, patients and vital public sector workers were being let down.

"I'm delighted the former First Minister is set to put an end to the game playing. The people of Gordon deserve better, just as they deserve an MP who will stand up for what's important to them, not chase their personal political agenda at the cost of what's best for the people of the North East. I intend to be a strong voice for all the people of Gordon."

Retiring Gordon MP Sir Malcolm Bruce added:"People in Gordon rejected the then First Minister's independence plans overwhelmingly at the referendum. I am sure that they would be delighted to have the chance to reject him again in May. Bring it on."