House Armed Services Committee Chairman Rep. Mac Thornberry pressed Republicans on the House Budget Committee Friday to approve a defense budget of at least $566 billion, in a letter that his Democratic counterpart called “an exercise in theater” if spending caps are not addressed.

The budget committee, led by Chairman Tom Price, R-Ga., is expected to release its spending guidance in the next two weeks. The committee’s figure will set the ceiling on spending for a host of modernization needs the Pentagon has pushed back due to years of war. So far, the committee has seemed reluctant to consider raising the spending limits beyond sequestration levels, and in the few public statements on the budget, has emphasized returning federal spending to lower levels.