Scottish independence: Alex Salmond says Yes campaign 'gaining ground'
The "Yes" campaign is gaining ground ahead of the independence referendum, Scotland's first minister has said.
But in an interview with the BBC's Reporting Scotland programme, Alex Salmond said there was "still a lot of work to do" to secure victory.
Mr Salmond also said he had changed his style of campaigning after previous defeats in national elections.
Earlier, Prime Minister David Cameron said people in Scotland "do not want to live in a foreign country".
In an interview with BBC Scotland's Sally Magnusson, Mr Salmond said he had "substantially changed" his style of campaigning ahead of the SNP's victory in the 2007 Scottish Parliament election to "accentuate the positive".
He said: "I realised - and it took me a while in politics - that people want to vote 'for' something as opposed to 'against' something.
"Since then I think people would have to accept that the electoral results tend to vindicate that approach.
"And also they are vindicating the approach to this campaign, because since November, when we launched the White Paper, the average support in all opinion polls for "Yes" has gone from 37% to 45%."
Mr Salmond added: "So gradually, month after month, we are gaining ground. We're not there yet, we have still got a lot of work to do, but the "Yes" campaign, because of our positive approach, which we are absolutely in thrall too and which we will keep to, is gaining ground as we explain the arguments to the people of Scotland."
Polls have suggested that women were less likely to vote for independence than men, but Mr Salmond said he believed the "Yes" campaign would close the gender gap.
He said: "There was a time when the SNP had that gender gap, but that gender gap has closed and in fact there was a poll just last week which showed the SNP ahead at Westminster among women voters. In terms of the independence vote, the polls have been picking up that more women are undecided.
"I have heard it said that it is because women are more risk averse. I don't actually think that is true. I think it is because women take a careful look at the issues and come to the conclusion.
"I think it is really, really important as the "Yes" campaign moves forward, that we concentrate on issues which explain independence in terms of a careful consideration, but also in terms of the progressive social change that can be brought about in Scottish society.
"Just because people take time to make up their mind doesn't mean that they're not going to move to "Yes"."
A House of Lords report published on Friday cast doubt on whether negotiations on independence in the event of a "Yes" vote could be concluded in time for the Scottish government's proposed independence date of 24 March 2016.
Mr Salmond denied he was making the process of achieving independence sound too easy, adding: "I think Scotland will be a more prosperous and, above all, a more equal society as an independent country.
"We will face challenges like every country faces, but we will have the ability to answer and respond to these challenges."
Speaking as he met secondary school pupils at Lockerbie Ice Rink earlier on Friday, Prime Minister David Cameron claimed Scots do not want to live or work in a "foreign country" after independence.
The union means people on both sides benefit from the "precious asset" of London, the Tory leader said.
He added: "Alex Salmond is making an extraordinary argument. London is an enormous and precious asset for the whole of the UK, and many Scots benefit from London's hub status and from working and investing in London and from the investment from London into Scotland.
"Now surely we should be making the most out of that connectivity, rather than separating ourselves from it.
"People in Scotland say to me 'I've got children working or studying in London', and people in London say to me 'I've got children working or studying in Scotland'.
"Do we really want to have a situation where they are working or studying in a foreign country?"
Voters will be asked the Yes/No question: "Should Scotland be an independent country?" in the referendum on 18 September.