Former chancellor Alistair Darling may have scored a narrow victory over First Minister Alex Salmond in the first live TV debate of the Scottish independence referendum campaign, a poll has suggested.

With just over six weeks to go till voters in Scotland decide if the country should remain in the UK or not, the two rival politicians took part in a sometimes heated and noisy debate over the nation's future.

A Guardian/ICM poll conducted immediately afterwards indicated Labour MP Mr Darling, the leader of the pro-UK Better Together campaign, had won the debate by 56% to 44%

But Scotland's Deputy First MInister Nicola Sturgeon told broadcaster STV, which had staged the independence clash: "I definitely think my side won."

She added there was "nothing about how we make our country more prosperous or how we make it fairer" from Mr Darling in the head to head showdown.

On which politician had made the best arguments in the debate, Mr Darling was also ahead in the ICM poll, with 51% of the 512 people questioned preferring the case he had made, compared to the 40% who said the SNP leader had made the better argument.

But almost half (47%) of those surveyed said the First Minister had the "more appealing personality", compared to 39% for the Better Together leader

The two hour long programme saw Mr Salmond and Mr Darling clash over key issues facing voters north of the border in the September 18 referendum.

Mr Darling, who was chancellor in Gordon Brown's Labour government, repeatedly pressed Mr Salmond to set out what his "plan B" would be if an independent Scotland failed to secure a currency union to allow it to retain the pound in the wake of a Yes vote.

Meanwhile the SNP leader challenged Mr Darling several times to say whether he agreed with comments from Prime Minister David Cameron that Scotland would be a successful independent country.

The Better Together leader also accused Mr Salmond of being ''ridiculous'' after a series of questions from the First Minister on comments said to have been made by the No campaign.

These included that Scots would have to drive on the right hand side of the road and would be more susceptible to attacks from outer space after independence.

Better Together campaign director Blair McDougall said the debate would " prove to be a huge, possibly decisive, moment in the referendum campaign".

He claimed: " Alistair Darling asked the questions Scotland needed answers to. The First Minister's failure to offer basic answers was there for all to see. Even the audience was turning against him as time went on.

"Alistair gave a strong performance but what matters more is that we believe his case will prove more persuasive with the remaining undecided voters."

Mr McDougall continued: " The nationalists had arrogantly said this would be Salmond's 'Bannockburn' - it may yet turn out to have been his Waterloo.

"There is a long way to go but this has been a great night for our campaign and for Scotland."

But Blair Jenkins, chief executive of the pro-independence Yes Scotland group, insisted the debate had resulted in a " clear win for the Yes campaign" with a "positive, optimistic and visionary case presented by the First Minister against another dose of negativity and scaremongering from Mr Darling".

Mr Jenkins said: " What Mr Darling presented was the No campaign's bankrupt vision for the future of Scotland. He not only failed to make a positive case for a No vote - he didn't even try.

"The First Minister presented the positive, compelling case for Scotland taking our future into our own hands and using our vast wealth, talent and resources to build a better and fairer country.

"And it is that positive vision that will win the day with a Yes vote on September 18."

Think tank Demos analysed the response to the debate on Twitter, which attracted some 104,000 tweets in total

Carl Miller, social media researcher at the think tank Demos, said: " Twitter was a new battleground which both campaigns urged their supporters to fill.

"But overwhelmingly for both candidates, it wasn't cheers but boos that filled this new digital arena and our analysis suggests people were turned off for one of the oldest reasons of all - neither politician was keen to answer the question.

"Our realtime analysis revealed that Scottish men were overwhelmingly vocal in sharing their opinions of the debate. Men were talking more about Salmond whilst women tweeted more about Alistair Darling. As for which side came out on top, it was a fairly even split with an equal share for the hashtags of each campaign."

At the start of the debate, which took place in front of an audience of 350 at the Royal Conservatoire of Scotland in Glasgow, Mr Salmond urged voters in Scotland to seize the opportunity independence with both hands.

He told them: ''My case this evening is this: no one, no one will do a better job of running Scotland than the people who live and work in this country.

''On September 18 we have the opportunity of a lifetime. We should seize that opportunity with both hands.''

At the end of the debate he said: ''Voting yes is a vote for ambition over fear. It tells the world that Scotland is an equal nation that carries itself with confidence and self-belief."

He added: " 'This is our moment - let's take it.''

Mr Darling opened by saying he wanted to " use the strength of the UK to make Scotland stronger".

With all three of the main parties at Westminster having drawn up proposals to transfer more power to Edinburgh in the event of a No vote, the former chancellor said: "We can have the best of both worlds with a strong Scottish Parliament, with full powers over health, over education and with more powers guaranteed.

''Because a vote to say no thanks to independence is not a vote for no change.''

Mr Darling went on: "I want to see Scotland prosper. I don't want to see new barriers, new borders, new boundaries where none exist. I don't want to see anything get in the way of the jobs and security that we need in this country.

''So let's say with confidence, let's say with pride, let's say with optimism, n o thanks to the risks of independence, and let's say let's have the best of both worlds not just for us but for generations to come.''

Mr Darling pressed the Scottish First Minister on the key issue of currency in an independent Scotland, demanding to know what Mr Salmond's "plan B" was if he failed to negotiate a currency union with the rest of the UK.

Chancellor George Osborne, Labour shadow chancellor Ed Balls and Liberal Democrat Chief Secretary to the Treasury Danny Alexander have all maintained they would not allow an independent Scotland to use the pound in such an arrangement

Mr Darling challenged Mr Salmond, saying: ''Contemplate for just one minute that you might be wrong. What is plan B?

''If you don't get a currency union what are we going to have instead? We need to know.''

The Labour MP went on: ''Any eight-year-old can tell you the flag of a country, the capital of a country and its currency. I presume the flag is the saltire, I assume our capital will still be Edinburgh, but you can't tell us what currency we will have. What is an eight-year-old going to make of that?''

Mr Salmond, raising his voice to be heard above shouts from the audience, stated: ''We will keep the pound because it belongs to Scotland much as much as it belongs to England. It's our pound as well as your pound.''

He said: " 'This is Scotland's pound, it doesn't belong to George Osborne, it doesn't belong to you, it's been built up by the people of Scotland over a long period of time.''

On the ''critical'' subject of an independent Scotland's place in the EU, Mr Darling questioned how long it would take to negotiate membership and what the terms of that would be.

''It's quite clear that Scotland would have to reapply, it's not at all clear what the term and conditions are that we'd have to meet," he said

But Mr Salmond countered that Mr Darling's allies in the No campaign wanted to take the UK out of the EU, arguing: " 'Isn't the real uncertainty that you have a government which is having an in-out referendum on Europe and you're in bed with people who will say that they're going to vote to leave the European Union. Isn't that the risk for Scotland?''

The two men also clashed on the finances of an independent Scotland, with Mr Darling insisting the country was better off in the UK.

''Money has flowed both ways over the last 30 years, but in the last 22 years Scotland has spent more than it has put in, so we have benefited from being part of the United Kingdom,'' he said.

''We have higher public spending here per head than they do in the rest of the United Kingdom.

''As someone who is fiercely proud of being Scottish I am not unhappy that from time to time we tackle problems in Liverpool, in Manchester, in Norwich, in Newcastle, because as well as being Scottish I regard myself as being part of something bigger.

''But we benefit from being part of the UK at the moment.''

Mr Salmond, however, insisted: ''In each one of the last 33 years, Scotland has paid more in tax per person than the average of the UK.

"Over the last five years we have £8 billion more into the Treasury than we have had out of it, in relative terms. That is £1,500 a head for every man, woman and child in Scotland.''