WASHINGTON ― Partisan sparring over the size of the defense budget marked the House Armed Services Committee’s debate of its annual policy bill Wednesday, highlighting the headwinds faced by the legislation.

Rebuking at the House bill’s $733 billion top line, which is $17 billion less than the Trump administration requested, panel Republicans threw their weight behind an amendment to add the money back. The GOP-controlled Senate is due to consider a rival $750 billion bill that passed the Senate Armed Services Committee in May.

If the committee’s hawkish Republicans vote against the bill in large numbers at the markup, the chamber’s Republicans will also vote against it, observers said.

In that scenario, Democrats would have to rally their own ranks ― a challenge when the number of progressives in the party have expanded since 49 Democrats voted against the annual defense policy bill last year.

HASC’s ranking member, Rep. Mac Thornberry, offered the measure to meet the administration’s request and the Pentagon’s unfunded acquisition priorities. In lockstep Wednesday, Republicans repeatedly argued that a $750 billion top line reflects the 3 to 5 percent minimum growth defense leaders have testified they need to counter Russia and China.

“That is what is required to continue to repair readiness and not fall behind critical areas with the Russians and Chinese,” Thornberry said “Hypersonics: We cut the administration’s request and we are behind in hypersonics.”