Image copyright Daily Mirror

John Bercow is demanding an apology from the Daily Mirror over claims he asked for £1m to appear on "I'm a Celebrity, Get Me Out of Here!"

The outgoing Commons Speaker has accused the paper of "publishing lies despite being advised of the truth" and has complained to the press watchdog.

The Mirror claimed talks between Mr Bercow and ITV broke down over the size of his appearance fee.

It said it stood by its story, which was based on "authoritative sources".

However, the newspaper also said it was "happy to accept" that Mr Bercow had "no serious desire to appear" on the programme.

Mr Bercow, who retired on Thursday after 10 years in the Speaker's chair, is understood to be furious about the story.

'Utterly trashy'

In a letter to the Mirror's showbiz editor, he said: "I must make it clear to you in the most uncompromising terms that I have not had the slightest interest now or at any time or an any basis to go on that programme."

He adds that he "did not at any time to anybody ask for £1m to go on the show, which I consider to be utterly trashy".

He demands an apology from the paper and threatens legal action, if the "false allegations" are repeated.

Image copyright PA Media Image caption John Bercow is waving goodbye to Westminster after 22 years as an MP and 10 as Speaker

The Mirror suggested representatives for Mr Bercow had been in talks with ITV about him appearing on the next series of the reality show, in which celebrities take part in a series of eye-watering challenges, such as eating insects or being trapped underground with snakes.

It said Mr Bercow had "allegedly demanded a £1m fee" for appearing in the next series, due to start in December.

This was £400,000 more than any previous contestant had received, the newspaper reported.

'Grave concern'

It suggested ITV had confirmed discussions had broken down over the question of Mr Bercow's fee, quoting an unnamed source saying "he has priced himself out of the market".

Mr Bercow has written to the Independent Press Standards Organisation to claim it is factually untrue and a breach of the editor's code.

In its response, the watchdog said: "We are looking at the points you raise, and will be in touch shortly."

In a text message to TV agent Nicki Clarke, who originally approached Mr Bercow with the idea of appearing, ITV talent producer Micky Van Praagh suggested the story was "obviously nonsense and I have no idea where it has come from".

She added: "ITV has not confirmed that talks broke down because of money. Please can you apologise to John for me for the story."

In an e-mail to Mr Bercow, Ms Clarke, who works for Shine Talent Management, said the story was "incredibly frustrating" and she had expressed her "grave concern" to ITV about it.

The Mirror said the story was "based on information from authoritative sources".

"We are confident that conversations took place between ITV and a representative for John Bercow about appearing on I'm a Celebrity and that these talks broke down over money," a spokesman said.

A host of politicians have appeared on I'm A Celebrity over the years, including Conservative MP Nadine Dorries and Boris Johnson's father, Stanley.

Last month, Boris Johnson joked that he would like to see Mr Bercow perform the infamous Bushtucker Trial and eat a kangaroo's testicle.