David Cameron has said "frustration" during the Scottish independence referendum campaign prompted his plea for the Queen to intervene but he now wanted to avoid making his indiscretion "worse".
It is understood that the former prime minister caused "an amount of displeasure" in Buckingham Palace earlier this week after revealing he sought the support of the Queen , who is meant to remain above the political fray.
In an interview with Sky News' Sophy Ridge on Sunday, Mr Cameron acknowledged his revelations, made in a BBC documentary, had caused consternation but defended his decision, saying the suggestion he had revealed details of a private conversation with the monarch was not "correct".
He said: "What I have said in that programme, and I don't want to add to it in any way, was about conversations between my aides and her aides, actually."
Explaining the context, he added: "Alex Salmond was saying that Her Majesty would be the proud monarch of an independent Scotland.
"There was a frustration in my team and that's why the conversations between one set of aides and another set of aides took place. But that's it."
When pressed further he added: "I don't want to say any more because I don't want to make the situation worse than it is."
Mr Cameron, who has been carrying out a media blitz to promote his memoirs, had told the BBC he made contact with Buckingham Palace officials in 2014, suggesting the monarch could "raise an eyebrow" in the closely-fought referendum campaign.
A few days before the referendum in September that year, the Queen told a well-wisher in Aberdeenshire that she hoped "people would think very carefully about the future".
The comment was seized on by many pro-union campaigners as an indication that the Queen was urging voters to keep the UK together.
And Mr Cameron told the BBC he thought the comments "helped to put a slightly different perception" on the campaign.
On Thursday, a palace source quoted by the BBC said "it serves no one's interests" for conversations between the prime minister and the Queen to be made public and "it makes it very hard for the relationship to thrive".
