Four female journalists on Wednesday began their sex and age discrimination case against British broadcaster the BBC, claiming they lost their jobs following a "rigged" recruitment exercise.

Martine Croxall, Annita McVeigh, Karin Giannone and Kasia Madera, who have all presented on the BBC's television channels, were present at Wednesday's preliminary hearing in London for the employment tribunal.

The full tribunal is due at a later date.

The four women claim that they were paid less than men in equivalent roles and that they unfairly lost their jobs at the BBC News Channel.

The BBC denies it underpaid them and said its application process was "rigorous and fair".

"It is denied that (the BBC) has subjected (the presenters) to age or sex discrimination, harassment or victimisation, or has breached the sex equality clause," the broadcaster said, according to court documents.

The BBC announced in 2022 that it planned to merge its domestic and international news channels.

The claimants say that the BBC privately told four other presenters -- two men and two younger women -- that they would keep their jobs.

"We were put through a pre-determined job application process in February 2023," the presenters told court.

They were instead offered jobs as correspondents, an effective demotion that came with a pay cut.

The BBC says that at least five other applicants achieved better scores during the recruitment process.

All four presenters also claim they have not been paid the same as equivalent male counterparts since February 2020.

"The BBC grinds you down on pay," Croxall, a chief presenter with the BBC News Channel and BBC World News since 2001, told the hearing.