Around 300,000 members of the political party of former French president Nicolas Sarkozy are voting for a new leader.
The opposition UMP has been without a head since Sarkozy lost the presidential election in May.
Fighting for the leadership is a man whose style of politics has been compared to that of the former president.
Jean-Francois Cope, who is UMP’s Secretary General, is advocating the party move further to the right and become an aggressive opponent of the socialist government – courting supporters of Marine Le Pen’s Front National.
However, Cope will have to beat the favourite – former prime minister Francois Fillon.
Fillon is warning that a move to right would cause a divide within the party, thus weakening it.
Having played such a large role under Nicolas Sarkozy, Fillon is also portraying himself as an experienced statesman.