The two candidates vying to be French president have gone head-to-head in a highly anticipated TV debate.

Conservative frontrunner Nicolas Sarkozy and Socialist Segolene Royal clashed over employment, the economy, the environment and law and order.

The only debate of the campaign was a heated confrontation, and continued beyond the expected two-hour duration.

The encounter was seen as a decisive battle in swaying undecided voters ahead of Sunday's second-round vote.

Sarkozy won 31.2% and Ms Royal won 25.9% in the 22 April poll.

On the attack

The face-off was screened by France's two biggest TV channels and watched by an estimated 20 million people.

Royal criticised Sarkozy's record in government during the debate, particularly on crime and security - Sarkozy's traditional forte.

"In 2002, Mr Sarkozy, you talked about zero tolerance, but today you can see that the French are very worried about the rise in violence and aggression in French society," she said.

The former interior minister defended himself, saying the figures showed violent crime had fallen.

The most heated exchange came during the second half of the debate as the contenders discussed school places for children with disabilities.

Royal accused Sarkozy of "political immorality" for dismantling socialist measures on the issue.

Sarkozy attacked his opponent for losing her temper - a criticism often levelled at Sarkozy himself.

The rivals also debated public sector reform and clashed over employment. Sarkozy said the 35-hour week, which was brought in by the socialists, had been a disaster for the economy. He said France needed to work more.

"She [Royal] still thinks that you have to share out the work like pieces of a cake," Sarkozy said. "Not a single country in the world accepts this logic, which is a monumental mistake".

He also criticised Royal's pension policy as vague.

Despite the clashes, neither candidate appeared to score a decisive blow, says the BBC's Alasdair Sandford in Paris.

They will be looking keenly at the opinion polls in the next few days to see whether they made the impact they were hoping for, our correspondent says.

Sarkozy and Royal are hoping to win votes from the 18% of voters who backed the third-placed candidate, centrist Francois Bayrou, as well as those who supported far-right nationalist Jean-Marie Le Pen.

'Decisive' moment

Former President Valery Giscard d'Estaing, who created the put-down "You don't have a monopoly of the heart" in the 1974 presidential election debate with his rival Francois Mitterrand, says that debate helped him win the election.

He predicts that the Sarkozy-Royal showdown will be "decisive".

But other commentators say more than 80% of French people have already decided how they are going to vote.

The last head-to-head presidential-race debate - Jacques Chirac versus Socialist Lionel Jospin in 1995 - drew 17 million viewers.

Chirac won the first of his two terms that year. In 2002, he refused to debate with Le Pen.

PHOTO CAPTION

France's UMP political party presidential candidate Nicolas Sarkozy speaks as he visits a retirement home for patients with Alzheimer's disease as he campaigns in Bourg-Blanc, France, May 1, 2007. (Reuters)

BBC