The Queen has said she hopes "people will think very carefully about the future" ahead of the Scottish independence referendum.
The comment was made to a well-wisher outside church near her Balmoral estate in Aberdeenshire.
It follows reports claiming the Queen was growing increasingly concerned about the 18 September vote.
Royal officials have insisted her comment did not breach the monarch's constitutional impartiality.
The Queen's comment came as she spoke to a member of the public outside the church at Crathie.
When the well-wisher joked that they were not going to mention the referendum, the Queen remarked: "Well, I hope people will think very carefully about the future."
Following previous reports that Her Majesty was growing increasingly concerned about Scottish independence, Buckingham Palace issued a statement which read: "The sovereign's constitutional impartiality is an established principle of our democracy and one which the Queen has demonstrated throughout her reign.
"As such, the monarch is above politics and those in political office have a duty to ensure this remains the case.
"Any suggestion that the Queen would wish to influence the outcome of the current referendum campaign is categorically wrong. Her Majesty is simply of the view this is a matter for the people of Scotland."
The BBC's royal correspondent Peter Hunt said: "This wasn't a slip of the tongue by the head of state of the United Kingdom - rather a reflection of how seriously, she like many others, views the significance of Thursday's vote."