(CNN) He's been called the "French Thatcher" for his apparent admiration of Britain's "Iron Lady" and willingness to tackle the unions.

On Sunday, Francois Fillon clinched the Republican party's presidential nomination, having beaten his closest rival Alain Juppe in a second-round vote.

He'd already dispatched former President Nicolas Sarkozy, in whose government he served as prime minister between 2007 and 2012.

French Republicans will be hoping he can do the same to Marine Le Pen, leader of the far-right Front National, in a popular vote for the French president in May next year

Mild mannered racing fan

The 62 year old lawyer-turned-politician grew up in a strict Catholic household in Sarthe, western France, to a notary father and history teacher mother.

At the age of 27 Fillon was elected mayor of Sable, and worked his way up the political ladder to become Sarkozy's mild mannered prime minster in 2007.

Sarkozy was such a big personality that a lot of people don't really know who Fillon is Aurelien Mondon

"Sarkozy was such a big personality that I think a lot of people don't really know who Fillon is," said Aurelien Mondon, senior lecturer in French politics at Bath University.

"Indeed one thing that could work against Fillon is his lack of charisma."

The father-of-five lives in a 12th century castle near where he grew up, with Welsh-born wife Penelope.

What does he stand for?

In a nutshell: Fillon aims to end the 35-hour work week, cut public spending, abolish the wealth tax, reduce immigration and invest 12 billion euros in security, defense and justice.

Tough on unions: French newspaper Liberation morphed Fillon's face with Margaret Thatcher's in a terrifying front cover this week -- no doubt inspired by the Republican's admiration of Britain's former prime minister, his French newspaper Liberation morphed Fillon's face with Margaret Thatcher's in a terrifying front cover this week -- no doubt inspired by the Republican's admiration of Britain's former prime minister, his tough talk on unions , and pledge to cut 500,000 jobs from the civil service.

Warmer on Russia: "Fillon wants to renew links with Russia and has been praising Russian politicians lately," said Mondon, adding: "It could put him in the same category as the populist right that is on the rise across Europe."

Critical of same-sex marriage: In 2013 Fillon voted against same-sex marriage, which came into law under President François Hollande.

"Fillon comes from the Catholic conservative side and is supported by radical Catholic organizations -- particularly the ones who organized anti-gay marriage demonstrations three years ago," explained Mondon.

Supported burkini ban: Fillon offered his support to the mayors who passed temporary burkini-bans over the summer. A court in Nice Fillon offered his support to the mayors who passed temporary burkini-bans over the summer. A court in Nice later suspended the city's ban.

Why he could be France's next president

Just a few weeks ago, Fillon was considered an unlikely bet for the presidency, but he won over voters with a polished performance in the TV debates.

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He apparently also struck the right tone on the fight against Islamist terrorism and ISIS after publishing a new book called "Beating Islamic Totalitarianism."

"Until recently we thought it would be Juppe or Sarkozy against Marine Le Pen in the presidential election," said Mondon.

"Le Pen would have done a lot better against Juppe, who could have been seen to be too moderate, and Sarkozy, who could have been seen as a hypocrite for not doing enough as president in 2007.

"Fillon has the credentials that neither of the other Republicans do with the radical right -- so that will make it a lot more difficult for Le Pen to compete against."