BRASILIA, March 12 (Reuters) - Brazilian President Dilma Rousseff's main coalition partner served notice on Saturday that it could break from her embattled Workers' Party government in 30 days and join opposition efforts to unseat the leftist leader.
At a rowdy convention of the fractious Brazilian Democratic Movement Party (PMDB), leaders quashed a motion by irate delegates who wanted to quit Rousseff's government immediately, before it goes down in a political storm over corruption and economic recession.
Instead the party agreed to put off that decision for 30 days and leave it to the party executive committee, ensuring its unity behind its leader Michel Temer, who is Rousseff's vice president.
Party insiders said this gives the PMDB time to gauge the level of support in the country for the impeachment of Rousseff sought by opposition parties in Congress, which could put Temer in the presidential seat.
"We cannot ignore that Brazil faces a very serious economic and political crisis," Temer said in a speech to the party's biennial convention.
Temer said the PMDB's program lays out a blueprint to stimulate business, reduce the size of government, create new jobs and restore growth to an economy that shrank 3.8 percent last year, its worst performance in 25 years.
The widening corruption probe surrounding state-run oil company Petrobras has turned many PMDB lawmakers against Rousseff, threatening to split her coalition and increasing chances of her impeachment in Congress this year.
The anti-Rousseff faction rallied the convention with chants of "Out with Dilma" and "Out with the Workers' Party" and "Temer for president."
"The government is corrupt. President Rousseff is isolated and cannot do anything. We should leave now," Senator Marta Suplicy, who quit the Workers' Party last year to join the centrist PMDB, told the convention.
"This government will fall, it cannot survive. Either we abandon ship now or go down with it," said Carlos Marun, a lawmaker from the farm state Mato Grosso do Sul.
If Rousseff is not impeached, Marun warned, Brazil's top electoral court could annul the Rousseff-Temer election win in 2014 in an investigation of graft money allegedly used to fund their campaign.
Several of the PMDB leaders standing next to Temer at the convention are themselves the target of corruption probes, including the speaker of the lower house of Congress, Eduardo Cunha, who has been indicted for laundering money in the Petrobras kickback scandal.
The PMDB, a party with no fixed ideology, has been in power ever since Brazil restored democracy in 1985 after two decades of military rule, either in the government or controlling one of the two house of Congress. It has six ministers in Rousseff's cabinet besides the vice presidency. (Reporting by Anthony Boadle; Editing by Mary Milliken)