5 MIN. DE LECTURA
(Adds PSD declaring will vote to impeach Rousseff, stock market close)
By Anthony Boadle and Maria Carolina Marcello
BRASILIA, April 13 (Reuters) - Brazil's President Dilma Rousseff pledged on Wednesday to form a government of national unity if she survives an impeachment vote in Congress this weekend, but the odds of that lengthened as allies continued to desert her.
A stream of defections from Rousseff's coalition makes it increasingly likely she will lose Sunday's ballot in the lower house of Congress on whether she should face trial in the Senate over accusations she broke budget laws.
Politicians have begun to flock this week to the residence of the man who would replace Rousseff if she is convicted, Vice President Michel Temer, to declare their support for him, his aides said.
Business leaders have also come out in support of Temer who promises market-friendly policies and less government intervention to boost the world's seventh largest economy, hit by its worst downturn since the Great Depression of the 1930s.
In a major blow for Rousseff, the largest centrist party remaining in the government's coalition, the Social Democratic Party (PSD), instructed its members to vote for the president's impeachment.
The party's leader in the lower house, Rogerio Rosso, told reporters on Wednesday evening the vast majority of the PSD's 38 deputies support Rousseff's ouster.
The move comes on the heels of the defection on Tuesday of another crucial ally, the centrist Progressive Party, or PP. The party, with 49 members in the lower house, left her government and pulled its one minister from her cabinet.
Meanwhile, the Republican Party and the smaller National Labor Party (PTN) were due to meet on Wednesday, but members said most of their fellow lawmakers would vote against Rousseff even as their leaders negotiated jobs offered by her government.
"They are running away from all parties except her own Workers' Party and the Communist Party of Brazil. It's a herd mentality," a leader of Temer's Brazilian Democratic Movement Party (PMDB) who is close to the vice president told Reuters.
He said the PMDB, which quit Rousseff's coalition two weeks ago, projects impeachment will clear the lower house with 380 votes on Sunday.
Temer said on Tuesday he was ready to form a transitional government with other parties to lead Brazil out of the political crisis, raising speculation he was already forming a shadow government.
"Obviously, he will start thinking about a cabinet on Monday if the vote is for impeachment on Sunday," Temer's press spokesman Marcio de Freitas said.
Battling for her political survival, Rousseff handed negotiations to win support against impeachment to her mentor and predecessor, Luiz Inacio Lula da Silva, Brazil's most influential politician despite a corruption investigation that has hampered his efforts to save her government.
"My first act after the vote in the lower house will be to propose a new pact among all the political forces, without winners of losers," Rousseff told Estado de S.Paulo newspaper in a briefing for local media.
She voiced confidence that her supporters would deny the opposition the 342 votes, equivalent to two-thirds of the lower house, needed to send her impeachment to the Senate.
Political risk consultancy Eurasia said Rousseff could still try to cobble together support from centrist parties, but it will be hard for her to stop the momentum for impeachment, with defections raising the odds of her removal to 70 percent from a previous estimate of 60 percent.
Rousseff's opponents are 18 votes short of victory in the lower house, with 324 lawmakers backing impeachment and 124 opposed, and 65 undecided or declining to respond, according to a survey by the Estado de S.Paulo newspaper.
The rift between Rousseff and her vice president reached breaking point on Monday over an audio message Temer sent his supporters calling for a government of national unity. Rousseff accused him of leading a conspiracy to overthrow her.
In an interview with Globo News on Tuesday, Temer denied he was plotting to become president, calmly stating: "If destiny takes me to that position ... I will be ready."
Temer's top economic adviser told Reuters that policies to gradually rebalance depleted public accounts, create jobs and raise income would be priorities for the vice president should he become the country's next leader.
Brazil's benchmark Bovespa stock index rose for a second consecutive day, closing up 2 percent on investor hopes a Rousseff impeachment will improve the prospects of an economic recovery.
The CNT transport sector lobby on Wednesday declared its support for impeachment saying Rousseff's government was incapable of drawing the investment needed to restore growth and lacked the political support to pass needed reforms.
In a letter to lawmakers, Brazil's most powerful industry lobby, the CNI, described the country's situation as "catastrophic" and blamed Rousseff's mistaken policies.
"It's time for change," the letter seen by Reuters said.
Additional reporting by Lisandra Paraguassú and Alonso Soto; Editing by Daniel Flynn and Andrew Hay