By Brian Love and Yann Le Guernigou
PARIS (Reuters) - The opposition Socialist Party comprehensively won French local elections Sunday as the far-right National Front surged, between them pressuring President Nicolas Sarkozy a year before he faces the electorate.
With most votes counted in the second round of polls to elect 'cantonal' councils in half of France, the left had 36 percent, almost double the ruling conservative UMP party's 18.6 percent.
The anti-immigrant National Front, which has surged in opinion polls under new leader Marine Le Pen, scored 11 percent even though it put up candidates in only a minority of departments. In some areas it scored as much as 40 percent.
Despite a low turnout of around 46 percent, the polls will be seen as the last big test of sentiment before the April 2012 election, set to pit the unpopular Sarkozy against left-wing rivals growing in strength and a surging far right.
The telegenic Le Pen has pushed ahead of Sarkozy to stand second behind leftists in opinion polls to gauge what the first round of a presidential election could look like.
The prospect that Sarkozy might not even make it into a runoff has caused alarm and disarray in the UMP.
Prime Minister Francois Fillon said the National Front's score "shows that the protest vote should not be underestimated or made light of. This party must be beaten and the reasons for its support must be clearly evaluated and dealt with."
Le Pen told reporters: "A few more pushes and shoves with the battering ram and the UMP system will disintegrate."
NATIONAL FRONT CHALLENGE
Sarkozy's UMP party has blurred the distinction with the far right by taking a tough line on the integration of France's large Muslim minority.
But the president's popularity ratings have sunk to record lows below 30 percent largely because of resentment over his austerity policies to rein in France's debt, as well as criticism of what critics call his gung-ho way of dealing with domestic and international issues.
Turnout Sunday was well up from around 36 percent in a first round last Sunday, where the Socialist Party came in first with 25 percent of votes, followed by the UMP with 17 percent and the National Front close behind with 15 percent.
The results give weight to polls showing that Le Pen, a tough-talking 42-year-old lawyer who took over from her blustery ex-paratrooper father in January, could score more than Sarkozy in the opening round of a presidential contest.
Jean-Marie Le Pen shocked France and the world when he made it to the second round of the presidential election in 2002.
The party now has a fresher face but is struggling to cast off an extremist image: it announced the expulsion Saturday of one of its local election candidates after a magazine website published a photograph of him doing a Nazi salute.
France's cantonal councils take care of matters such as the building of roads and schools as well as the distribution of various welfare subsidies. Cantons are administrative units within France's 100 departments.
The Socialists had urged supporters to vote conservative if necessary in the second round to shut out the National Front, traditionally cast as a political pariah by mainstream parties.
Sarkozy's UMP had urged right-wingers to shun the National Front, but not necessarily by voting Socialist.
(Additional reporting by Lionel Laurent, Gerard Bon and Emil Picy; Writing by Catherine Bremer; Editing by Kevin Liffey)