The prospect that France may soon elect its first president from outside an established party in nearly a century is fuelling concern about potential political instability.
Opponents of Emmanuel Macron, the independent who has emerged as the surprise frontrunner in the country’s most unpredictable election in decades, claim he would struggle to govern because he would be unlikely to muster a parliamentary majority.
Flanked by supporters waving tricolour flags at a rally in Marseille on Saturday, Mr Macron, 39, a fresh-faced former investment banker who has never held elected office and would be the youngest president in modern French history, sought to appeal to conservative voters.
Describing himself as a “patriot”, he stressed that he would cut taxes, take a tough line on terrorism and plough more than £4 billion into helping France’s struggling farmers.
He will need conservative backing to defeat Marine Le Pen, the Front National leader. Polls show the mainstream Republican and Socialist candidates face being eliminated in the first round of the election in three weeks’ time, leaving the two outsiders facing each other in the final showdown in May.
Mr Macron will trounce Ms Le Pen, according to the polls, but only if voters unite against the far-Right.
Supporters of the conservative candidate, François Fillon, the former favourite who has been undermined by corruption allegations, argue that if elected, Mr Macron would be forced to rely on fickle support from moderate Socialists and the centre-Right.
Despite the extensive powers invested in the French presidency by Charles de Gaulle in 1958 following the collapse of a series of weak governments, Mr Macron’s ambitious centrist programme of business-friendly reforms could be blocked by a fragmented or hostile parliament.
Mr Fillon and Ms Le Pen accuse Mr Macron of being heir to the unpopular president, François Hollande, because he is backed by several leading top leading Socialists.
But Mr Macron told a crowd of thousands: “I am the heir of your energy, of your yearning for change.”
Hours before the rally he held surprise talks with Christian Estrosi, the influential Right-wing president of the southern region that includes Provence, the Riviera and the Alps.
Mr Estrosi is ideologically close ideologically to Mr Fillon but they fell out when Mr Estrosi urged him to stand down amid accusations that he and his British wife had embezzled public funds.
Mr Estrosi was booed by Mr Fillon’s supporters at a meeting on Friday. If Mr Macron wins the presidency, he hopes that the fledgling political movement he has created from scratch in barely a year will secure a majority in parliamentary elections in June.
Unlike the two mainstream parties, Mr Macron’s group, which is called En Marche! (On The Move), has yet to choose its candidates for France’s 577 constituencies.
It has had received some 14,000 online applicantstions online from supporters who are excited about Mr Macron’s pledges to cut red tape and his promise that half the candidates will be women, but many have never before stood for office.
Bruno Cautrès, a political analyst with the CEVIPOF think tank, said: “Emmanuel Macron is charismatic nationally but he will need strong, locally known parliamentary candidates. Even big names have been beaten by popular local figures when they’ve been parachuted in by the main parties.
“The only scenario in which there would be no problem with a majority would be if François Fillon wins (but) it looks doubtful because his image has been so badly tarnished.”
The campaign is growing more venomous by the day, with Mr Fillon accusing Mr Macron of being a “fraudster” and Mr Macron hitting back at him and Ms Le Pen for what he describes as their “campaigns of hate”.