The head of Brazil's lower house of congress says the government doesn't have the votes to pass social security reforms that are key to President Michel Temer's agenda — and possibly his survival in office.

Rodrigo Maia said Tuesday that the reforms are the only straightforward solution to the country's economic crisis. But he said the government cannot muster the 308 votes needed to pass such a constitutional amendment in the 513-member lower house.

Polls show Temer is deeply unpopular, and he's been counting on such reforms to revive the economy and help save his presidency.

Failure to pass the reforms could undermine crucial business support for Temer. And that could leave him vulnerable to congressional efforts to have him suspended to face corruption charges.