Image copyright Andreas Wolff Image caption The "Yes" and "No" sides will be campaigning across Scotland

A row over the intervention of business leaders and banks in the Scottish independence debate has intensified on the final weekend of campaigning.

First Minister Alex Salmond said the Scots would not be "bullied" by oil companies, supermarkets or London.

It comes as chief economist at Deutsche Bank David Folkerts-Landau said voters and politicians had failed to grasp the negative consequences of independence.

Meanwhile, a Guardian/ICM poll put the "No" vote at 51%, with "Yes" on 49%.

On Thursday evening a YouGov opinion poll was published suggesting that the "No" campaign was leading by 52% to 48%, once undecided voters were excluded.

The Yes Scotland campaign claims that over the weekend there will be more than 35,000 volunteers at 473 registered street stalls trying to persuade people to vote for independence.

They say that 2.6 million "Yes" leaflets will be delivered in 48 hours.

Scotland's Deputy First Minister, Nicola Sturgeon, said: "The 'Yes' campaign has been carried along by a flourishing of self-confidence among people in Scotland.

"That momentum is still growing and will soon become unstoppable, as people reject the Downing Street-orchestrated campaign to talk Scotland down.

"Today thousands of Yes supporters from communities across Scotland will be running the biggest campaign day of action Scotland's ever seen."

The bosses of three retail groups have put their names to a letter in the Daily Record, in which they claimed their costs would rise in an independent Scotland and they would have to take "the difficult decision" whether or not to pass those on to consumers.

The letter, signed by the heads of Marks and Spencer, B&Q owner Kingfisher and Timpsons, read: "Within our group there is first-hand experience of trading across national borders - in France, Ireland and across the world.

"Our experience is that it always leads to more red tape and higher costs."

However Tim Martin, the boss of pub chain JD Wetherspoon, said on Friday: "Scotland could do very well on its own".

Police complaint

Ahead of the final weekend of the campaign, Mr Salmond has renewed his complaint that the Treasury broke ministerial rules when it confirmed to journalists that the Royal Bank of Scotland (RBS) planned to relocate its registered headquarters from Edinburgh to London in the event of a "Yes" vote.

He has written to Sir Jeremy Heywood, the UK's most senior civil servant, asking "which minister or official authorised the release [of the information about RBS]" and "at what time the information was released".

BBC economics editor Robert Peston said he had been told the Treasury briefed journalists about the plans to potentially move to London before the board of RBS had formally approved the decision.

Our correspondent said that when journalists were emailed on Wednesday evening by the Treasury, to tell them about the relocation plans of RBS and Lloyds, RBS's board "was still meeting" to decide whether to tell shareholders the following morning.

Image copyright Getty Images Image caption Former Prime Minister Gordon Brown will continue to campaign for Better Together over the weekend

He said sources had told him they did not believe it was a case of market abuse, or the illegal release of price sensitive information, because the UK and US stock markets were shut at the time of the briefing.

Police Scotland have confirmed they have received a complaint from RBS shareholder Peter de Vink, a supporter of independence for Scotland, alleging the UK government leaked market-sensitive information about the bank.

Mr de Vink said Downing Street "has been behaving like a dictator in a banana republic," adding that the UK government's behaviour was "a total affront to democracy".

He said he had written to Scotland's senior prosecutor, the Lord Advocate as well as Police Scotland, the City of London Police and the Financial Conduct Authority.

A referendum on whether Scotland should become independent is to take place

People resident in Scotland will be able to take part in the vote, answering the "Yes/No" question: "Should Scotland be an independent country?"

The referendum will take place on Thursday, 18 September 2014

Go to the BBC's Scotland Decides page for analysis, background and explainers on the independence debate.

Great Depression

And Deutsche Bank's Mr Folkerts-Landau has said it was "incomprehensible" that Scotland was even contemplating withdrawal from the UK.

The chief economist compared a potential "Yes" vote to the mistakes which led to the Great Depression of the 1930s.

"A 'Yes' vote for Scottish independence on Thursday would go down in history as a political and economic mistake as large as Winston Churchill's decision in 1925 to return the pound to the Gold Standard or the failure of the Federal Reserve to provide sufficient liquidity to the US banking system, which we now know brought on the Great Depression in the US," he said.

Media playback is unsupported on your device Media caption Deutsche Bank global strategist Bilal Hafeez said an independent Scotland would no longer have the Bank of England as a lender of last resort

Deutsche Bank's global strategist Bilal Hafeez also said independence would bring a depression to Scotland and possibly the rest of the UK.

He told Radio 4's Today it was "very, very difficult" to make a case for Scotland flourishing as an independent country.

"Essentially the issue is that if Scotland was to break away from the Union, but retain the pound... Scotland would lose control of the pound, it would have to accept whatever monetary policy was set for the rest of the UK. It would not have control of the money supply in the country.

"More importantly, it wouldn't have a central bank that can issue pounds - that power would reside with the bank of England."

However, the Scottish government accused Mr Folkerts-Landau of failing to take into account Scotland's "strong fiscal position".

Scottish Finance Secretary John Swinney said Scotland would start life as an independent nation "from stronger economic foundations than any other nation in history".

Speaking in Perth on Friday evening, First Minister Alex Salmond said: "The people of Scotland are not going to be bullied by big oil. We're not going to be bullied by big supermarkets. We're not going to be bullied by big London government.

Image copyright Getty Images Image caption The "Yes" campaign will focus on Scotland's wealth, job-creating powers and the NHS

"We're not going to be bullied out of our opportunity - our once in a lifetime opportunity - to create a more prosperous country and a fairer society."

Across the final weekend of campaigning, Mr Salmond is due to continue his helicopter tour of the country, including stops in Oban, Dumfries, Ayr and Glasgow.

Former Prime Minister Gordon Brown will be campaigning for Better Together, as will Labour MP Jim Murphy, who will complete his 100-town tour of Scotland.

Thousands of Orange Order supporters were in Edinburgh for a rally on behalf of the United Kingdom.

Ahead of the march, Henry Dunbar, grand master of the Orange Order in Scotland, said: "The 'No' campaign has been criticised for not showing enough passion for the Union - well look out, here comes some passion.

"We are the Orangemen and women of Scotland and we are passionate about our Queen and country."

On Thursday voters in Scotland will go to the polls to answer the Yes/No question: "Should Scotland be an independent country?"