Independence is supported by about a quarter of adults in Scotland, according to a poll.
The survey of more than 1,000 people was taken in the days around the publication of the Scottish Government's White Paper on independence.
The results show 26% back a Yes vote, up one point on polls from September and October.
Backing for a No vote, at 42%, is one point down on October and two points down on September, the poll by TNS BMRB suggests.
Around one-third remain undecided.
Among those who say they are certain to vote, the results change to show 31% support for independence and 46% against.
Tom Costley, head of TNS Scotland, said: "It's almost as if opinion in Scotland was marking time before the publication of the White Paper.
"Once we get into 2014, we can expect the debate to gather pace ahead of the September referendum, and we may begin to see some shifts in opinion, especially with so many people clearly waiting to be convinced one way or another. The examination of the White Paper will be an important part of that debate."
The results come days after a different poll was taken on attitudes to independence after the release of the White Paper.
The separate survey, conducted by Progressive Scottish Opinion, put support for a Yes vote at 27% and support for a No vote at 56%.
A Better Together spokesman said: "The fact that support for Scotland going it alone remains below historic levels shows that people are increasingly rejecting Alex Salmond's politics of division and grievance.
"Although this poll is encouraging, there is no room for complacency. The Nationalists only need to win once and by one vote to break up the UK forever.
"We will be campaigning every day to make our strong positive case to people who have yet to make up their mind that we are stronger and better together as part of the UK."
Blair Jenkins, chief executive of Yes Scotland, said: "Yet another poll shows a shift away from No to a Yes vote, leaving a third of voters in Scotland still undecided. This means a swing of less than 8% would put the Yes vote in front.
"The No campaign has lost almost one-fifth of its supporters over the last year, which is not surprising given the 'can't do' negativity of a campaign that describes itself as 'project fear'.
"It is now clear what a Yes vote will mean for Scotland, with important gains and guarantees for people across the country.
"The big question marks are over the costs of a No and that is why their support is in freefall."
Why are you making commenting on The Herald only available to subscribers?
It should have been a safe space for informed debate, somewhere for readers to discuss issues around the biggest stories of the day, but all too often the below the line comments on most websites have become bogged down by off-topic discussions and abuse.
heraldscotland.com is tackling this problem by allowing only subscribers to comment.
We are doing this to improve the experience for our loyal readers and we believe it will reduce the ability of trolls and troublemakers, who occasionally find their way onto our site, to abuse our journalists and readers. We also hope it will help the comments section fulfil its promise as a part of Scotland's conversation with itself.
We are lucky at The Herald. We are read by an informed, educated readership who can add their knowledge and insights to our stories.
That is invaluable.
We are making the subscriber-only change to support our valued readers, who tell us they don't want the site cluttered up with irrelevant comments, untruths and abuse.
In the past, the journalist’s job was to collect and distribute information to the audience. Technology means that readers can shape a discussion. We look forward to hearing from you on heraldscotland.com
Comments & Moderation
Readers’ comments: You are personally liable for the content of any comments you upload to this website, so please act responsibly. We do not pre-moderate or monitor readers’ comments appearing on our websites, but we do post-moderate in response to complaints we receive or otherwise when a potential problem comes to our attention. You can make a complaint by using the ‘report this post’ link . We may then apply our discretion under the user terms to amend or delete comments.
Post moderation is undertaken full-time 9am-6pm on weekdays, and on a part-time basis outwith those hours.
Read the rules hereComments are closed on this article