An independent inquiry to determine Carrie Symonds’ role in the “governing” of the UK should be launched, a Conservative think tank has said.

The Bow Group called for a review to clarify the “position and authority” of the Prime Minister’s fiancee, amid concern over her influence within Number 10.

It said the inquiry should look at Ms Symonds’ role in Downing Street, details of any official meetings she has attended, and orders given by her to special advisers and civil servants.

The group, which describes itself as the oldest conservative think tank in the world, said the inquiry should also look at her “possible influence” in Government hiring and appointments.

It comes after two allies of Ms Symonds Baroness Finn and Henry Newman, were appointed as key advisers in Number 10.

Ben Harris-Quinney, chairman of the Bow Group, said Ms Symonds “currently holds no official role in the Conservative Party or the Government, yet consistent reports in the press suggest that Ms Symonds is taking a central role in running the country, without any authority or accountability to do so”.

He added: “She has not been elected, she has not been appointed, she holds no legal or constitutional powers to make decisions relating to who should hold government posts, to be party to privileged information, or to set the policy direction of the country.

“It is therefore urgent that a review and inquiry takes place to determine what Ms Symonds’ role in the governing of the United Kingdom is, and has been to date.

“Failure to clarify Ms Symonds’ position and authority, and to ensure that Ms Symonds is not and cannot take any action in governing the United Kingdom, potentially has huge hazards for the Government, the Conservative Party, and the nation.

“The public take a very dim view of cronyism, democracy in Britain is and must always be sacred, and no one should be involved in running our country without accountability to the people.”

Patrons of the Bow Group include Conservative peers Lord Tebbit and Lord Lamont, as well as MPs John Redwood and Sir Bill Cash and former MP Ann Widdecombe.

A spokeswoman for Ms Symonds declined to comment.