The conservative party of former President Nicolas Sarkozy is expected to dominate the final round of France's local elections, give the far-right National Front another electoral breakthrough and deal a new blow to the governing Socialists.

Voters casting ballots Sunday are choosing 4,108 local council members across the country who will make up 98 councils. For France's leading parties, the stakes are high.

Sarkozy and Socialist Prime Minister Manuel Valls have been working the campaign trail — catching up to the most visible campaigner, far-right leader Marine Le Pen. Her anti-immigration National Front placed second in last week's first round with 25 percent of the vote, behind the conservatives.

Valls has called on Socialists to vote for conservatives to block the National Front, which looks toward the 2017 presidential race.