PARIS (Reuters) - French former prime minister Francois Fillon has gained ground among conservative Les Republicains supporters and is poised to beat hitherto favorite Alain Juppe to the party's presidential nomination, according to a poll published on Tuesday.

Juppe, the mayor of Bordeaux, remains in pole position for the first-round primary vote on Nov 20, although his support has fallen seven percentage points to 33 percent, according to the Opinionway poll for Atlantico.

But Fillon, now tied with former president Nicolas Sarkozy for the first round, would pick up more votes to beat Juppe if he progresses to the second, the survey suggested. A series of recent polls have shown growing support for the Paris lawmaker.

Opinionway contacted a sample of 828 voters who firmly intended to vote in the Les Republicains primaries.

The French presidential election takes place, also in two rounds, in April and May.

(Reporting by Laurence Frost; Editing by Robin Pomeroy)