By Patricia Zengerle and Roberta Rampton
WASHINGTON (Reuters) - President Barack Obama is set on Friday to veto legislation allowing families of victims of the Sept. 11 attacks to sue Saudi Arabia: a move that could prompt the U.S. Congress to overturn his decision with a rare veto override.
Congress overwhelmingly passed the Justice Against Sponsors of Terrorism Act earlier this month in reaction to long-running suspicions, denied by Saudi Arabia, that hijackers of the four U.S. jetliners that attacked the United States in 2001 were backed by the Saudi government.
The White House has said Obama will veto the bill on the grounds that other countries could use the law as an excuse to sue U.S. diplomats, service members or companies. Obama has until midnight to do so.
But if two-thirds of the lawmakers in each of the Senate and House of Representatives vote to overturn Obama's veto, the law would stand, and would be the first such override of his presidency.
It was not immediately clear when Congress would vote on the measure. Lawmakers’ most pressing business is to come up with a spending bill to keep the government open beyond Sept. 30.
A group of survivors and families have pressed Congress to uphold the legislation.
"Fifteen years has passed without answers or accountability for the most horrific attack on America - we are angry, frustrated and tired,” said Terry Strada, whose husband was killed at the World Trade Center.
White House officials have been pressing their arguments with lawmakers in hopes of averting an override.
But some prominent Democrats in Congress have said they will stand by the legislation.
"I’ve worked with these families for a very long time, and I think they should have their day in court," House Democratic Leader Nancy Pelosi told reporters on Thursday.
The Saudi government has lobbied heavily to stop the bill, as has the European Union.
Major U.S. corporations like General Electric and Dow Chemical have also pressed lawmakers to reconsider.
"The bill is not balanced, sets a dangerous precedent, and has real potential to destabilize vital bilateral relationships and the global economy," GE Chief Executive Jeffrey Immelt said in a letter to Senate Majority Leader Mitch McConnell, who backs the legislation.
(Reporting by Roberta Rampton and Patricia Zengerle; Editing by Phil Berlowitz)