Only half of people who support Scottish independence are strongly in favour of it, a new poll has found.
A YouGov poll commissioned by the pro-Union Better Together campaign found that 31% of people favour independence, with 16% strongly supporting it and 15% who "tend to support it".
Of the 56% the poll found to be opposed to independence, 37% were strongly against it. The study of 1,011 people was carried out two days after the First Minister and the Prime Minister signed the referendum agreement in Edinburgh. It shows that there is support for independence from people who identify themselves with political parties other than the SNP.
When asked about their voting intentions for Westminster, 5% of people surveyed who supported the Conservatives also back independence, while 21% of Labour supporters and 17% of Liberal Democrat voters are also in favour. The poll found that 11% of people who intend to vote for the SNP at Westminster are opposed to independence.
Blair McDougall, Better Together's campaign director, said: "This poll reveals a deep lack of confidence, even amongst instinctive supporters of independence, in the proposition of breaking up the UK. The longer the SNP put off answering the most basic of questions on independence the more people will lose confidence in leaving the UK.
"Would the EU demand Scotland sign up to the euro? Would we have to agree our public spending limits with London? What would the cost of borrowing be for Scotland? These are not questions that can wait to be answered in a few paragraphs of a White Paper next year. Our campaign will be fighting for every vote between now and the referendum in two years' time. We will be asking the difficult questions of the nationalists and we will be celebrating all that is good about a strong Scotland with the strength and security of the UK."
A spokesman for Yes Scotland, the cross-party pro-independence campaign, said: "This poll clearly shows that people of different political colours support independence and as a broad church movement we very much welcome that. The historic Edinburgh Agreement signed this week marks only the beginning of the independence debate.
"People in Scotland are seeking information and over the next two years we are confident that, as the choices become clearer, the economic and social benefits of an independent Scotland will lead to a Yes vote in 2014. Independence is about taking responsibility for making our own decisions according to our own values, priorities and aspirations. An independent Scotland will usher in a new social union that will strengthen our friendship and relationship with the rest of the UK."
An SNP spokesman said: "What this poll shows is that already over a quarter of Labour voters in a Scottish Parliament election and nearly a third of LibDem voters support an independent Scotland, while overall support for a Yes vote has risen by 3% in under two weeks.
"We are confident that come the referendum in two years' time, the people of Scotland will vote Yes for an independent Scotland which protects and builds on the achievements of Home Rule, and reject a no campaign which would roll back the gains Scotland has made since 1999."