“Failure to clarify Ms Symonds’s 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,” said Ben Harris-Quinney, the Bow Group chairman.
“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.”
The call comes as Ms Symonds is believed to have played a part in the shock departure of Oliver Lewis, the head of the “Save the Union” unit – as she had in the earlier ousting of Dominic Cummings.
Two of her close friends have recently been appointed to key No 10 roles, senior adviser Henry Newman and Simona Finn, the new deputy chief of staff who hosted Ms Symonds’s 30th birthday celebrations.
Although her depiction by critics as a Lady Macbeth figure has sparked accusations of sexism, no one denies she enjoys significant influence way beyond that of previous partners of prime ministers.
Ms Symonds is keen to soften the government’s image, through the departure of Vote Leave veterans including Mr Cummings and Mr Lewis, and push forward the green agenda as a committed environmentalist.
The Bow Group, which is independent of the party despite its strong Conservative links, said Ms Symonds – who is not a special adviser – was therefore not accountable to any minister.
That meant she had also not been security vetted, giving her authorisation to view privileged government information.
An inquiry should be held in public and hear testimony from current and former Downing Street staff, with the release of the records and correspondence, the group said.
“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,” Mr Harris-Quinney 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.”
The pandemic put on hold Mr Johnson’s plans to marry Ms Symonds last year. She gave birth to their son Wilfred in April, just 17 days after the PM left hospital having battled Covid-19 himself.
Join our commenting forum
Join thought-provoking conversations, follow other Independent readers and see their replies