Nadine Dorries has announced she is standing down as Culture Secretary following Boris Johnson’s departure from No 10.

Sources close to the Tory MP – who was a prominent supporter of Liz Truss during the leadership election – said she believed it was the right time to go.

It is understood she was given the opportunity to carry on in Cabinet but had chosen instead to return to the backbenches.

It is expected that she will now be given a peerage in Mr Johnson’s resignation honours list, triggering a by-election in her Mid Bedfordshire constituency.

During the leadership campaign, Ms Dorries was an outspoken critic of Rishi Sunak – in one controversial tweet likening him to Brutus stabbing Julius Caesar over the way he had turned on Mr Johnson.

She accused fellow Tory MPs of staging a “coup” against the outgoing Prime Minister, telling BBC Panorama: “I was quite stunned that there were people who thought that removing the Prime Minister who won the biggest majority that we’ve had since Margaret Thatcher in less than three years.

“Just the the anti-democratic nature of what they’re doing alone was enough to alarm me. And for me it was a coup.”

She was also among Mr Johnson’s most outspoken defenders during the ‘partygate’ saga, calling an investigation by the Commons Privileges Committee into whether he lied to MPs a “witch hunt”, adding it represented the “most egregious abuse of power”.

Ms Dorries was appointed Culture Secretary in September last year, having previously served as health minister.

As a minister she was involved in drawing up legislation to curb social media companies through the Online Safety Bill and led controversial moves to privatise Channel 4.

Her term was also marked by a number of gaffes, primarily confusing rugby league with rugby union at an event to promote the upcoming Rugby League World Cup.

Ms Dorries stunned a rugby league audience in St Helens by referring to Jonny Wilkinson’s match-winning drop goal for England in the 2003 Rugby Union World Cup final in Sydney.

She later said the gaffe helped boost attention for the sport, telling MPs “rugby league has never had so much publicity and so much attention for the game”.

Ms Dorries was born in 1957 in Liverpool and grew up on a council estate, which she writes about on her official website, saying: “I am one of the luckiest people alive, to have grown up on a Liverpool council estate from the nineteen fifties to seventies.”

She started her working life as a nurse before pursuing a career in business, opening a child daycare business before becoming a director at Bupa.

Her career as a writer has seen her author more than 10 books, among them The Four Streets Quartet novels, as well as The Angels series about the nurses of Lovely Lane and her collection also includes The Tarabeg Trilogy.

Before being elected to Parliament as MP for Mid Bedfordshire in 2005, she worked for three years as an adviser to the former shadow home secretary and shadow chancellor Oliver Letwin.

Ms Dorries was thrust into the limelight in 2012 when she was suspended from the Conservative Party for appearing on I’m a Celebrity … Get Me Out Of Here without informing the chief whip first.

However she was readmitted to the party in May 2013.

Ms Dorries has been embroiled in a string of controversies throughout her tenure as an MP.

In 2009, when MPs’ expenses claims were revealed by the Daily Telegraph, she admitted she had got taxpayers to foot the bill for a lost £2,190 deposit on a rented flat.

And in 2010, she was rebuked by parliamentary standards commissioner John Lyon for misleading her constituents on her blog about how much time she spent in mid-Bedfordshire, admitting that it was “70% fiction”.

The mother to three daughters has also frequently been at odds with what she thought of as her party’s image, memorably referring to David Cameron and George Osborne as “arrogant posh boys”, while describing herself as “a normal mother who comes from a poor background and who didn’t go to a posh school”.

Having sold more than 2.5 million copies of her books, the 65-year-old’s departure from Government is expected to enable her to return to writing.