The embodiment of the political establishment is suddenly favourite to face Marine Le Pen in next year’s election

In an exhibition hangar near Lyon airport as thousands of supporters waved French flags, a well-heeled country gentleman seen as the figurehead of the traditional Catholic provincial French right, took to the stage with a contented smile.

François Fillon, the former prime minister who in a 35-year political career has come to embody the very essence of the French political establishment, shouted to the well-dressed, largely elderly crowd: “We have to change the system!”

Fillon is the dark horse who is suddenly favourite to win the right’s nomination for presidential candidate on Sunday, and thus likely to face the far-right Front National’s Marine Le Pen in the race to lead France next year.

Anare an echo of what the rightwing Nicolas Sarkozy promised when he swept to power in 2007, but failed to deliver.

Facebook Twitter Pinterest Fillon and Nicolas Sarkozy in 2010, when they were prime minister and president. Photograph: Charles Platiau/Reuters

Fillon was Sarkozy’s prime minister for five years, and would normally bear part of the blame for the failures of the Sarkozy era. But he has broken free of the stigma that haunted the former president and – styled as “Mr Austerity” – now promises to go further than any French leader has dared before, raising the retirement age, transforming labour laws and praising Thatcher’s Britain as a model success story.

It is, however, Fillon’s social conservatism and “family values” – including his private views on abortion and his drive to