By Adrian Croft
PARIS (Reuters) - Conservative candidate Francois Fillon is fighting to save his political career in France's presidential election after his campaign was hit by a fake jobs scandal.
Once the clear favourite, Fillon's campaign was plunged into crisis when a satirical weekly reported in January that his wife, Penelope, had been paid hundreds of thousands of euros for doing little work, including several years as his parliamentary assistant.
Fillon also paid two of their children for work as lawyers when he was a senator between 2005 and 2007.
The former prime minister has denied wrongdoing. But the affair and the combative way he reacted to it has undermined a wholesome image that Fillon, 63, a practising Catholic with 36 scandal-free years in politics, had cultivated. [nL5N1FM5MI]
It also exposed him to allegations of hypocrisy since he proposes shock treatment for the French economy, including sharp cuts in public spending, cutting half a million public sector jobs and scrapping the 35-hour working week.
Fillon sits behind far-right leader Marine Le Pen and centrist Emmanuel Macron in the polls, but still nurses hopes of forcing his way into the May 7 runoff between the top two candidates in the April 23 first round.
An admirer of former British Prime Minister Margaret Thatcher, Fillon is a social conservative who wants to limit adoption rights of gay couples. He has also called for warmer ties with Russia.
A consummate political insider, Fillon has cast himself as the man to deliver the "deep transformation, almost a revolution" he says France needs after years of slow growth under Socialist President Francois Hollande.
"My plan is the only one radical enough to get us out of the economic rut ...," he said in an op-ed for Les Echos newspaper.
Fillon fought on after magistrates put him under formal investigation over the fake jobs affair in March despite having said earlier that he would withdraw if that happened.
Despite resignations by campaign aides and polls showing most voters wanted him to withdraw, Fillon resisted pressure from within his The Republicans party to step down.
The fraud investigation was later widened to include luxury tailoring Fillon received as gifts, a judicial source said.
Fillon fought back, alleging he was the victim of a government plot to destroy his candidacy by spreading damaging media leaks about him. He alleged the plot went right up to Hollande - an allegation denied by Hollande's office.
Fillon had pulled off an upset in the conservative primary, beating former president Nicolas Sarkozy and former prime minister Alain Juppe.
Born in the Sarthe region some 200 km (125 miles) west of Paris, Fillon was the youngest member of parliament when first elected 36 years ago.
Despite holding a variety of ministerial posts over the years, Fillon has generally kept a low profile.
Sarkozy, who appointed Fillon as his prime minister from 2007 to 2012, once famously described him as effectively no more than a senior employee.
Despite his mild, refined demeanour, Fillon showed his mettle as social affairs minister in 2003 when he faced down street protests over his retirement pension age reforms.
Fillon, who has five children with his British-born wife, loves driving racing cars at the famous Le Mans circuit near his political fiefdom in the west of France.
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(Additional reporting by Brian Love and Sophie Louet; Editing by Richard Balmforth)