FRENCH President Nicolas Sarkozy switched his focus to immigration and security yesterday as he attempted to win over far-right voters in the presidential election campaign.

While centre-left Francois Hollande won the first round by 28.6% to 27.1% over Mr Sarkozy, it was National Front leader Marine Le Pen who stole the show by picking up 18%, the highest tally ever for a far-right candidate.

Opinion polls said 57-year-old Mr Hollande was likely to win the decider, with between 53% and 56% of the vote.

However, Ms Le Pen's strong showing offered Mr Sarkozy – the first sitting president to ever lose a first-round vote – an unexpected ray of hope.

He said: "I will continue to uphold our values and commitments: respect for our borders, the fight against factories moving abroad, controlling immigration, the security of our families."

Communist-backed hard-leftist Jean-Luc Melenchon, whom polls showed at one stage challenging Ms Le Pen for third place, finished fourth on 11.1%, ahead of centrist Francois Bayrou with 9.1%.

On a strong turnout of 80.2%, more than one-third of voters cast ballots for protest candidates outside the mainstream, foreshadowing a possible reshaping of France's political balance of power at parliamentary elections in June.

Pundits said Mr Hollande appeared to have larger reserves of second-round votes than Mr Sarkozy, who would need to pick up at least three-quarters of Ms Le Pen's supporters and two-thirds of Mr Bayrou's to win.

Polls suggested that between 48% and 60% of Ms Le Pen voters planned to switch to the President, while Mr Bayrou's backers split almost evenly between the two finalists, with one-third undecided.

Ms Le Pen said she would give her view on the run-off at a May Day rally in Paris next week.

However, she wrote off Mr Sarkozy as a departing president that would leave his party "in ruins".

National Front vice-president Louis Alliot suggested it was "unlikely" Ms Le Pen would endorse either candidate as things stand.

Financial market analysts say whoever wins in two weeks' time will have to impose tougher austerity measures than either candidate has admitted during the campaign, cutting public spending as well as raising taxes to cut the budget deficit.

If Mr Hollande wins, joining a small minority of left-wing governments throughout Europe, he has promised to renegotiate a European budget discipline treaty signed by Mr Sarkozy.

That could cause tension with German Chancellor Angela Merkel, who made the pact a condition for the provision of further assistance to troubled eurozone states.

The prospect of friction is causing some concern in financial markets, as is Mr Hollande's focus on tax rises over austerity at a time when sluggish growth is threatening France's ability to meet deficit-cutting goals..

Dominique Barbet, economist at BNP Paribas, said: "We've got a vote that is much more uncertain than we thought it would be.

"There's going to be some pretty hard campaigning, and the markets aren't going to like that.

"It's not going to be a very pro-European campaign."