2010 redistricting of French legislative constituencies

The Constitutional Council of France approved the redistricting of electoral boundaries in February 2010 to reflect France's changing demographics. The population ratio between the most populated and least populated constituencies was reduced from the 1986 redistricting results of 1:3.6 to 1:2. In effect, the number of seats increased in areas held by the center right coalition led by Union for a Popular Movement at the expense of the Socialist-led coalition.

Since the last redistricting effort in 1986, 577 constituencies of the National Assembly of France have been distributed among the Departments of France. In France, constituencies are divided in proportion to their population, based on 1986 census figures, each consisted of 108,000 inhabitants. In theory, the number of total constituencies located within a département is supposed to be proportional to the larger population within that département compared to the total population of France. (In total, there are 101 départements, which are grouped into 22 metropolitan and five overseas regions.) However, using French Republican tradition, each département must have at least two constituencies regardless of population. This, however, distorts the proportionality of national representation, with 23 départements being under-represented (including 5 of "two deputies" départements) and 28 départements over-represented. Effectively, 51 out of 101 départements were poorly represented based on the results of the most recent census.

A review of electoral boundaries will be conducted, based on demographic changes, after the second general census of the population following the previous border definition.

For instance, judging by representation in the National Assembly, the vote of someone in Lozère is worth more than three times the vote of someone in Bouches-du-Rhône; three votes in Saône-et-Loire is worth five votes in Réunion; and three votes in Moselle is equivalent to five Haute-Garonne. The 25 most populous départements – which together hold more than 50% of the French population – have one deputy in the National Assembly for every 114,512 inhabitants, while the 25 least populated départements have one deputy for every 80,220 inhabitants. This results in a ratio between the most and the least populated of 143 to 100, or, five residents for the smaller départements are worth seven resident in the major départements. The situation is exacerbated by demographic trends in the 1990s and their resulting disparities within départements. For example, in the Var, the population of the 1st constituency (the southern city of Toulon) was 73,946 inhabitants while that of the 6th constituency (Brignoles) was 180,153 inhabitants, resulting in a ratio of 1 to 2.44. These causes result in the most extreme expression of representational inequality, where the votes of two people living in the least-populated constituency of France (excluding overseas communities), Lozère’s 2nd constituency, weigh as much as eleven people in the most populous constituency, Val-d'Oise’s 2nd constituency.

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