The Queen and Prince Phillip
The Queen and Prince Phillip at yesterday's highland games in Braemar, Scotland. Getty

The pro-independence 'Yes' campaign has pulled ahead for the first time in polls on the Scottish independence vote.

Some 51% of Scots intend to vote for Scotland to become an independent country in the September 18 referendum, with the 'Yes' campaign having overturned a 22-point lead for the pro-unionist 'No' campaign.

Of those polled, 49% said that did not want Scotland to become and independent country.

The YouGov poll conducted for the Sunday Times excluded undecided and abstaining voters.

The momentum seems to be with the 'Yes' campaign, led by the Scottish National Party's first minister Alex Salmond, to break Scotland's 300-year union with England.

A Buckingham palace source told the Times that the Queen does not support Scottish independence, and that "there is now a great deal of concern" over prospect of the dissolution of the union, with the monarch asking for daily updates on the progress of the campaign.

Secessionist campaigners urged their side to remain focussed.

"While this poll puts us marginally ahead, other polls show that we still have more progress to make if we are to win," said 'Yes' campaign chief executive Blair Jenkins.

Polls show a tight race

Alistair Darling, leader of the Better Together campaign said that the polls show that the vote "will go down to the wire".

"It is not the Battle of Britain," he added, "It is the battle for Scotland, for Scotland's children and grandchildren and the generations to come. This is a battle we will win," he said.

Responding to the poll, chancellor George Osborne said that in the next few days new plans will be revealed to hand more powers to the Scottish parliament.

He told the BBC: "You will see in the next few days a plan of action to give more powers to Scotland, more tax powers, more spending powers, more powers over the welfare state."

"That will be put into effect the moment there is a 'No' vote in the referendum."

However, a poll conducted for the 'Yes' Scotland campaign put the pro-unionists ahead by 52% to 48% when undecided voters were excluded.

A Downing Street source told the BBC that Prime Minister David Cameron believed that there was "only one poll that matters" and that he would "strain every sinew" to make the case for the Union.