Paris (AFP) – French presidential candidate Francois Fillon was fighting to keep his campaign alive Thursday as a TV interview with his wife added fuel to fake job claims and some members of his party openly plotted to replace him.

One of France’s main investigative news programmes, Envoye Special, is set to air previously unseen footage on Thursday of Fillon’s British-born wife Penelope talking to a journalist in 2007.

Envoye Special presenter Elise Lucet told AFP that “several interesting phrases” had been found in the long-forgotten interview, including that she had never been her husband’s parliamentary assistant.

The British journalist who did the text version of the interview for the Sunday Telegraph newspaper, Kim Willsher, told AFP she did not recall the phrase in question and that she had never seen the complete video.

The interview was “not a political interview, it was a ‘wife of’ piece,” she said.

Fillon had been leading the presidential race until allegations emerged in the Canard Enchaine newspaper that his wife earned a pre-tax income of 830,000 euros ($900,000) as a parliamentary assistant over more than a decade — despite no-one recalling her ever working at the National Assembly.

A poll on Wednesday showed Fillon would crash out in the first round in April behind far-right leader Marine Le Pen and 39-year-old centrist Emmanuel Macron, who is rising fast in the polls.

– Conflicting camps –

Facing a judicial investigation over his wife’s supposed role, 62-year-old Fillon has flatly denied the accusations and insists the previously low-profile Penelope worked for him.

Two of the couple’s children were also employed as his parliamentary assistant at one point, earning an additional 84,000 euros before tax.

The accusations are highly damaging for Fillon, who campaigned as a sleaze-free economic reformer who would slash public spending by cutting 500,000 civil servants’ jobs.

An MP from his Republicans party said Thursday that an open letter was being drawn up by some members of the party calling for Fillon to be replaced by his 71-year-old rival Alain Juppe if he decides to stand aside.

“The letter is being finalised and is ready to be signed by several dozen lawmakers,” Republicans MP Philippe Gosselin told RMC radio.

A new poll showed almost seven out of 10 voters want Fillon to quit the race and Juppe was their preferred choice to replace him.

Juppe, a former prime minister who was once convicted over a party funding scandal, was selected by 33 percent of the 946 people questioned online for Harris Interactive on Wednesday.

But Republicans lawmakers who support Fillon published their own letter, claiming that the allegations against him were designed to prevent power switching from the Socialists to the right.

“We give Francois Fillon our complete support because his commitment to France is vital,” they wrote in rightwing newspaper Le Figaro.

The signatories included Francois Baroin, a former finance minister who has also been spoken of as a possible replacement for Fillon.

Meanwhile, the surprise winner of the leftwing nomination for the election, Benoit Hamon, was Thursday meeting President Francois Hollande as he searches for support within the fractured Socialist party to mount a credible challenge.

Hamon, a 49-year-old radical leftwinger with an ambitious proposal to pay a universal basic income in a world of dwindling work, will probably need to gather the votes of Communist-backed Jean-Luc Melenchon to stand any chance.

Hollande, who decided not to run for a second mandate after a trouble-plagued five years in power, has remained silent since Hamon beat centrist former Manuel Valls in Sunday’s primary runoff.