On a visit to Edinburgh, Mr Cameron indicated he thought the former First Minister was behind reports that the SNP would push ahead with a another vote without securing the agreement of the Conservative administration.
The Prime Minister was reacting to reports that a senior SNP source believed a Yes vote in such a plebiscite would be enough to deliver independence even though the constitution is reserved to Westminster.
A legally binding referendum can only take place with the permission of the UK Government.
The SNP source was reported as saying he believed that if another vote was held tomorrow Scotland would vote for independence.
Asked about the reports, Mr Cameron said he didn’t think a second referendum was “remotely on the cards”.
The Prime Minister said: “I tend to take at face value what Alex Salmond says on the record, rather than off the record. And on the record he said this was a once in generation, potentially once in a lifetime opportunity. I’m sticking with that.”
It was denied tonight by the SNP that Mr Salmond was the source. A spokesman said: “Mr Salmond has not advocated an unofficial referendum, on or off the record.”
Ms Sturgeon has maintained that the SNP did not campaign for a second referendum during the General Election.
Ms Sturgeon’s spokesman said the call for a second referendum were “totally wrong” adding “there are no such plans”.
The spokesman said: “The position is crystal clear: the general election was not a mandate for another referendum. And there will only be a another referendum if and when the people of Scotland back such a proposal at a Scottish parliament election.”