SAO PAULO (Reuters) – Presidential hopeful João Doria, the mayor of Brazil’s largest city, made it clear on Monday that he is not married to the centrist Brazilian Social Democracy Party (PSDB) and is open to courtship from other parties.

The stance of the rising young star of Brazilian politics will put the PSDB under pressure since his mentor and party stalwart, Geraldo Alckmin, the governor of Sao Paulo, also plans a presidential bid in next year’s elections.

“I will become a candidate the day I declare and have the support of a party,” Doria told reporters after addressing a business conference in Sao Paulo on Monday, without naming the PSDB.

While he has not announced that he will run, the 59-year-old self-made millionaire and former TV presenter has said he would accept if nominated by his party.

A Datafolha poll in June showed Doria is little known by Brazilian voters compared to Alckmin, but he has a far lower rejection rate and is on track to become more popular than the governor, who lost a presidential bid in 2004 to Workers Party incumbent Luiz Inacio Lula da Silva.

Alckmin has said publicly that he intends to run in the Oct. 7 election and favors a U.S.-style primary if the PSDB has several contenders for the nomination.

Doria opposes holding a primary and has not ruled out quitting the party.

In an interview published on Monday by the Estado de S.Paulo newspaper, the mayor said the party should pick its candidate based on who the opinion polls say is more popular.

Doria said he would continue in the PSDB but that other parties were reaching out to him and he left open the option of leaving to run for president.

“I intend to continue in the PSDB, until some circumstance prevents me from doing so,” he told the newspaper in Paris, where he met on Friday with French President Emmanuel Macron, a similarly young untested politician who rapidly rose to office.

Doria, an outsider who won his first election last year in a landslide victory for Sao Paulo mayor, has become a potential favorite center-right candidate offering an fresh clean face among Brazil’s corruption-plagued political class.