Support for independence falls back to 23%

The total is the same as the previous low recorded in 2010, and is nine points down on 2011, when 32% backed independence.

A further 61% backed devolution; 11% wanted to Scotland to remain in the UK without its own parliament; and 5% were undecided.

The figures were based on face-to-face interviews with more than 1200 voters between July and November 2012.

They were published by the Scottish Centre for Social Research (ScotCen) in a report co-written by Professor John Curtice of Strathclyde University, the country’s leading polling expert.

Asked a differently-worded question about where power should lie, 35% of voters said the Scottish Parliament should take "all the decisions for Scotland," down from 43% the previous year.

Six out of 10 voters (59%) said they would be "quite" or "very" worried if Scotland became independent, up from 46% in 2011. Only 21% say they feel confident about the prospect.

There was also a fall in the number of Scots expressing optimism about a range of issues if the country leaves the UK.

The latest figures show 42% believed an independent Scotland would have a stronger voice in the world, down from 51% in 2011. The proportion believing independence would instil a greater sense of national pride fell from 67% to 55%.

On the crucial issue of the economy - which ScotCen believes will decide the outcome of the referendum in 2014 - Scots were also slightly more pessimistic overall than the previous year.

Some 34% said independence would improve the economy (unchanged from 2011), while the same number believed it would make it worse, up from 29%. A further 23% said it would make no difference, while 9% were unsure.

As expected, support for independence was much stronger among those optimisic about the economic impact. Half of all voters who predicted an improvement in the economy wanted to leave the UK. Among the 6% of voters who said the economy would be "a lot" stronger, support for independence rose to 73%.

The Scottish Social Attitudes Survey revealed that the SNP Government’s efforts to promote independence since it came to power in 2007 have failed to translate into support for the policy. Backing averaged 30% from 1999 to 2006, compared to 26% over the course of Alex Salmond’s time as First Minister.

Voters also appear sceptical of Yes campaign claims that independence would deliver a fairer and more socially just society. Only 19% believed the gap between rich and poor would be smaller under independence, compared with 25% who thought it would increase. A further 47% said it would not make any difference. Of those who believe the gap would narrow, only 38% support independence.

"This suggests the issue is not central to most people’s views of the merits or otherwise of independence," said ScotCen’s report.

While the findings showed falling support for independence, they revealed a strong appetite for more devolution. Nearly two-thirds (64%) said Holyrood should take "most of the important decisions for Scotland" about welfare and benefits, compared to 19% who wanted control to remain at Westminster.

More than half (56%) believed Holyrood should take the lead in deciding tax levels. The Scottish Parliament will become responsible for setting a portion of income tax from 2016 but the IPPR think tank, which is close to Labour, recently called for Holyrood to be given much greater control. It said income tax should be fully devolved as part of reforms which would put MSPs in charge of 60% of the money they spend.

Asked about "devo max" - which would give Holyrood full economic powers but leave Westminster responsible for defence and foreign policy - Scots appeared less worried than they were by the prospect of independence. Fewer than a third (32%) said they would be worried by devo max, compared with the 59% anxious about independence.

Mr Curtice said: "During the course of the last 12 months, the independence debate moved firmly to the top of the Scottish political agenda. Yet the proponents of independence have apparently struggled to capitalise on the resulting opportunity to persuade Scots of the merits of their case. Instead more voters appear to have become concerned about the prospect of leaving the UK."

Reaction to the survey was mixed.

Secretary of State for Scotland Michael Moore said: “We are making a strong and positive case for Scotland staying in the UK family and even more people in Scotland are agreeing with us. The fact support for separation has fallen to 23% and is at an all-time low shows people simply do not believe there are convincing arguments to leave the UK.”

Scottish Labour’s constitutional spokeswoman Patricia Ferguson said: "This survey shows how successful and popular devolution is, and how out of touch this SNP Government really are. The people of Scotland are really concerned about jobs and a strong economy, and not separating from the rest of the UK."

Scottish Conservative leader Ruth Davidson said: "This survey shows Alex Salmond is failing spectacularly to sell his dream of separation to the people of Scotland, who are growing increasingly sceptical about the concept."

Scottish Liberal Democrat leader Willie Rennie said: “This survey shows people are attracted to our plans for Home Rule in a federal UK and repelled by the SNP plans for independence. We want a substantial transfer of financial and constitutional power that chimes with public opinion. This is bad news for the SNP as fear of the nationalists’ plans is high and support for independence low.”

But Blair Jenkins, chief executive of the Yes Scotland pro-independence campaign said: “Much of the field work for this survey was carried out prior to the Edinburgh Agreement and at a time when it was still a possibility that devo-max was an option for inclusion on the referendum ballot paper.

“Since the poll was conducted from July to November last year, we have had the Westminster welfare changes, making one million Scots families worse off, and the UK Government threatening to take us out of Europe, our largest trading market. "That said, a significant finding at this stage is that support for the Scottish Parliament making all decisions is 35%, the most popular option in this poll.

“A Yes vote is the way for the Scottish people to get the control over the future that they want.”

The SNP declined to comment on the survey but endorsed Mr Jenkins’ views.

A Scottish Government spokeswoman said: "A clear majority think the Scottish Parliament should make most of the ‘important decisions for Scotland’ about the level of taxes (56%) and welfare benefits (64%) - both of which are still largely controlled by Westminster – and over a third (35%) say Holyrood should make all decisions for Scotland.

"An independent Scotland is the only option on offer which meets these aspirations and which will mean the Scottish Parliament has the full powers we need to build the country we want to be."