WASHINGTON — Interest rates on new student loans are going to double because the Senate does not plan a vote before Monday’s deadline.

The chairman of the Education Committee and other Democrats said Thursday that the Senate would vote on July 10 on a one-year extension of the current interest rates. Without congressional action, rates on subsidized Stafford loans are set to go from 3.4 percent to 6.8 percent on July 1.

Iowa Sen. Tom Harkin says lawmakers could pass a bill that retroactively lowers rates after they double on Monday.

A previous attempt in the Senate to extend rates for two years failed to overcome a procedural hurdle.

The House has already passed a student loan proposal.