WASHINGTON – The Senate is the newest arena in the election-year face-off over federal student loans, and both sides are starting out by pounding away at each other.

With Congress returning from a weeklong spring recess, the Senate plans to vote Tuesday on whether to start debating a Democratic plan to keep college loan interest rates for 7.4 million students from doubling July 1. The $6 billion measure would be paid for by collecting more Social Security and Medicare payroll taxes from high-earning owners of some privately held corporations.

Republicans want a vote on their own bill, which like the Democrats’ would freeze today’s 3.4 percent interest rates on subsidized Stafford loans for one more year. It would be financed by eliminating a preventive health program established by President Barack Obama’s health care overhaul.