In the first round of the election last Sunday, the far-right candidate, Cendrine Le Chevallier, wife of the National Front mayor of the town, topped the poll with 39.5 per cent of the vote. The candidate of the centre- right UDF alliance was eliminated with only 22 per cent of the vote.
Ms Le Chevallier, seeking to replace her husband, who was disqualified for infringing campaign finance rules, needs to attract less than half of the centre-right vote to beat her Socialist opponent and take the seat in the run-off tomorrow.
This is not guaranteed: there was a very low turn-out in the first round last Sunday (only 45 per cent) and a somewhat different cast of electors may take part this weekend. Some local and national leaders of the traditional right have been urging their voters to block the Front at all costs: others have been silent or neutral, or have, implicitly, favoured a far-right victory.
The Toulon by-election has, therefore, confirmed the utter disarray of the French centre-right parties, split raggedly down the middle after the regional elections in March in a dispute over unauthorised local alliances with the Front.
Even though Toulon is well-established as a National Front town - the most racist town France, it is sometimes said - a victory for Ms Le Chevallier would be a substantial coup for the extreme right in France. It would be only the second time in normal conditions that the National Front had won victory by a full majority of voters: ie with more than 50 per cent of the vote.