Portman, a former budget adviser to Republican presidents, said four or five of his Democratic colleagues in the Senate have expressed interest in his draft legislation.
Historically low individual tax rates expiring at the end of the year and automatic spending cuts could push the U.S. economy into recession, congressional budget estimators have said.
Still, action is not expected until after the November 6 elections, and a revamp of the tax code is expected to be pushed back until next year.
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(Editing by Anthony Boadle)
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