Carrie Johnson, the wife of Britain's prime minister, is an experienced political operative in her own right who has been thrust from the shadows as allegations of sleaze and scandal envelop Downing Street.

The 33-year-old former head of communications for the Conservative party has kept a low public profile since Boris Johnson entered Number 10 in 2019.

She has given no interviews, and only appeared by Johnson's side at marquee events such as international summits and last October's annual Tory conference.

But she has increasingly been accused of holding too much sway over issues close to her heart -- especially the environment and animal rights -- and over staff appointments.

Much of the offensive has come from the prime minister's embittered former chief aide, Dominic Cummings, and has taken on new prominence in a new biography by Michael Ashcroft.

Prime Minister Boris Johnson's wife Carrie is accused of holding too much sway in the scandal-hit Downing Street operation, but supporters accuse her critics of sexism
Prime Minister Boris Johnson's wife Carrie is accused of holding too much sway in the scandal-hit Downing Street operation, but supporters accuse her critics of sexism AFP / Ben STANSALL

"My book shows Carrie's behaviour is preventing the prime minister leading Britain as effectively as the voters deserve," Ashcroft, a former deputy chairman of the Conservatives, wrote last weekend.

Supporters say the charges smack of sexism, and political opponents of Johnson say he and not his wife must be held to account.

After the first instalment of Ashcroft's book was published in the Mail on Sunday newspaper, her spokeswoman dismissed the claims as part of a smear campaign against the couple by "bitter ex-officials".

Carrie Johnson, she said, was a "private individual who plays no role in government".

Carrie Johnson took on a more prominent role by her husband's side at the G7 summit in June in southwest England, here welcoming South Korea's President Moon Jae-in and his wife Kim Jung-sook
Carrie Johnson took on a more prominent role by her husband's side at the G7 summit in June in southwest England, here welcoming South Korea's President Moon Jae-in and his wife Kim Jung-sook POOL via AFP / Adrian DENNIS

Most recently, the Johnsons have been accused of attending, or even hosting, some of the lockdown-breaking parties under police investigation at Downing Street.

Both are expected to face questioning from London's Metropolitan Police force.

That comes on top of a Caribbean holiday and the redecoration of the Downing Street flat funded by rich backers, along with a controversy about the evacuation from Kabul of pets sheltered by a British former soldier being allegedly prioritised over people.

"The Mustique holiday, Downing Street wallpaper, Afghan dogs, at least one Downing Street party... Carrie Johnson's name keeps coming up in relation to all these, sometimes unfairly, sometimes not," Paul Goodman, editor at the influential blog ConservativeHome, has noted.

Others have rallied to her defence, including Health Secretary Sajid Javid, who employed her as a special adviser in 2016. He branded her treatment unfair, "undignified" and rooted in sexism.

"I think the partners of politicians should be off-limits," he said.

Carrie Johnson and her husband Boris own a rescue dog, a Jack Russell-cross named Dilyn
Carrie Johnson and her husband Boris own a rescue dog, a Jack Russell-cross named Dilyn AFP / Oli SCARFF

However, Cummings has claimed she wanted to "get rid" of him from Number 10, and alleged she tried "to change a whole bunch of different appointments".

Ash Sarker, from the left-wing outlet Novara Media, agreed some of the criticisms were "motivated by misogyny".

"But she is also a political operator in her own right... and we don't have the normal methods of holding her accountable," she told Sky News.

Born Carrie Symonds, she is the daughter of the co-founder of The Independent newspaper and a former lawyer. She grew up in southwest London and attended a private school before studying theatre and art history at university.

She began working for the Conservatives in 2010, in marketing, and first came into contact with Johnson working on his 2012 re-election campaign for London mayor.

She then held various jobs in politics and at Tory party headquarters, including director of communications, but left that role in 2018 after a reported dispute over her expenses.

She joined the marketing team at conservation group Oceana, before moving to a role at The Aspinall Foundation, an animal welfare charity.

The Johnsons reportedly began dating in 2018 when the prime minister, now 57, was still married to his second wife.

When he succeeded Theresa May in July 2019, Carrie Symonds looked on with staff as he became the first British prime minister since Edward Heath in 1970 to take office without a spouse by his side.

She initially remained living elsewhere.

But the couple announced their engagement in early 2020, once his divorce was finalised, and wed in a "secret ceremony" in May last year.

In between, the couple's first child together, Boris Johnson's sixth, was born in April 2020, soon after he recovered from Covid.

The couple named him Wilfred. A baby girl called Romy followed in December.

The Johnsons own a rescue dog, called Dilyn, who also stands accused of varying degrees of misbehaviour in Downing Street.