WASHINGTON (Reuters) - Bipartisan Senate sponsors of a bill that would slap duties on some Chinese exports to the United States if it does not realign its currency said on Tuesday the measure enjoyed strong support in Congress and would likely pass.

The bipartisan legislation crafted by Senators Charles Schumer, a New York Democrat, and Lindsey Graham, a South Caroline Republican, was on a "fast train" for passage in the legislature, said Kansas Republican Senator Sam Brownback.

Years of discussion had not lead to significant movement on the vexing currency issue and "we're fed up," said Schumer, flanked by co-sponsors, including both senators from the struggling industrial state of Ohio.

Graham said that President Barack Obama's administration should "speak the truth" and label China a currency manipulator in a semiannual report due on April 15.

(Reporting by Doug Palmer and Paul Eckert; editing by Jackie Frank)