An Abergavenny woman hotly tipped to become the next First Lady of France has been embroiled in a political scandal set to sink her husband’s presidential bid.

Penelope Fillon is now under investigation following accusations she was paid large amounts of public money for work she did not perform whilst employed by her husband, frontrunner Francois Fillon.

The probe follows a report by the satirical Le Canard Enchaine newspaper that Mrs Fillon received 500,000 Euros of public cash for a phantom occupation.

The scandal, strong even for French political standards, threatens to torpedo Mr Fillon’s bid for the Elysee. His poll numbers have cratered by ten percent since the accusation was made public last week.

Although employment of family members is not illegal under French law, Mrs Fillon is accused of receiving funds for a job she did not carry out. The accusation is particularly damaging for her husband’s bid as he has modelled himself as the antidote to political sleaze.

Mr Fillon, who beat Nicolas Sarkozy and Alain Juppe to Les Republicans nomination in November, insists he paid his wife the sum for her employment as a parliamentary assistant. He recently described the fiasco as a ‘plot’ to bring down his bid.

Mrs Fillon was also questioned by police after it emerged she was paid €100,000 for 18 months’ work on La Revue des Deux Mondes, a literary review owned by French businessman Marc Ladreit de Lacharrière. The review’s former editor said he was unaware of Mrs Fillon’s employment.

Prosecutors are not expected to reach a decision on the case for at least a month. Senior party figures are said to believe the scandal dubbed ‘Penelope-gate’ could prove fatal as support ebbs away from Mr Fillon toward rival Marine Le Pen, and centrist media favourite Emmanuel Macron.

Mr Fillon still tops the polls, although French political commentators now expect the race between Ms Le Pen, of the Front National, and Mr Fillon, to tighten.