Labour made the mistake in the Nineties of allowing the SNP to “monopolise” the saltire, the Scottish Secretary admittd yesterday.

“We allowed our national symbol - the St Andrew's Cross - to be co-opted as an image of nationalism,” Jim Murphy said.

In doing so, Labour repeated its mistake of the 1980s when it had allowed Margaret Thatcher to “claim the mantle of patriotism” and wrap herself in the Union flag, he added.

Mr Murphy's comments came as a poll found that fewer than a third of voters in Scotland want independence.

Twenty eight per cent of those questioned by ICM for BBC Scotland said they wanted to break away from the rest of the UK, compared to 47 per cent who want to remain within the Union but with Holyrood being given enhanced powers, and 22 per cent who want to stay within the UK but with Westminster retaining control of tax and spending.

In his speech yesterday, Mr Murphy sought to reclaim the saltire and to argue there was no contradiction between Scottish and British identities. It has has long been a view held in private by many in Labour circles.

But a leading politics expert dismissed the comments as “irrelevant to contemporary Scotland”.

Professor James Mitchell, of Strathclyde University, said: “Scottish politics has moved well beyond flags. What Labour needs to do is decide what it believes in, not which flag it should be waving.”

He attacked the claim that Labour had abandoned the saltire, saying that it was much used by the party during the 1997 devolution referendum campaign.

Since becoming Scottish Secretary, Mr Murphy has been keen to shed Labour's image as a London-dominated party - the reason blamed by some for the loss of the Holyrood election in 2007.

His speech on Britishness, a favourite theme of Gordon Brown, is part of Labour's fightback as it continues to trail the SNP in the polls.

Mr Murphy described Scottish devolution as the “best of both worlds” and in an attack on nationalism he added: “Multiple identities sum up the complexity of human life. Single identities can be a breeding ground for division, intolerance and aggression.”

The SNP yesterday dimissed Mr Murphy's claim that it had hijacked the saltire. A spokesman said: “If Labour has got an identity crisis in Scotland it is one of its own making with Gordon Brown having pursued his Britishness agenda for narrow political reasons south of the Border.

“Jim Murphy's comments say more about Labour's discomfort with that agenda than anything about the SNP. The saltire is Scotland's national flag and open to anyone to use.”

The poll of 1,010 people, commissioned by the BBC to mark a decade of devolution, also found that 56 per cent of people wanted a referendum before Holyrood's powers are increased.

When asked who should make most of the decisions for Scotland about income tax, 62 per cent said the Scottish government and 34 per cent the UK Government.

The question of who should have responsibility for old age pensions received a similar response, with 65 per cent saying it should be devolved to Holyrood, and 32 per cent wanting control retained at Westminster.

The poll found that defence and foreign affairs should continue to be handled by Westminster. Thirty five per cent believed they should be decided by the Scottish government, but 63 per cent wanted the UK Government to continue to have responsibility.

Alex Salmond said that the poll was a boost for Holyrood on its tenth birthday.

“As a whole it is extremely good news for those who believe in the Parliament, and those who want to see the Parliament grow in influence and regard,” the First Minister added.

Mr Murphy said it was right that the Parliament should have more powers: “We get the best of both worlds here. We have a Scottish government looking after things like the health service and the education system and we also have the British Government, led by a Scot, dealing with things like the economy, welfare, international development and social security.”

The Calman Commission into Scottish devolution has recommended giving Holyrood greater control over income tax and other areas including stamp duty, land tax, airgun legislation, powers over drink-driving and speed limits and the running of the Scottish elections.

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