Mr Fillon, speaking on French channel TF1, said there was nothing improper or illegal about his employing his wife, Penelope, as his parliamentary aide for years.


He said “her work was real” and that he would give explanations to investigators.


Mr Fillon said: “Only one thing would prevent me from being a candidate: it’s if my honour was harmed, if I were given preliminary charges.”


Prosecutors opened a probe into suspected embezzlement and misappropriation of public funds after it was reported that Mr Fillon’s wife was paid about 500,000 euro (£424,000) for a job she allegedly did not do.