Wednesday’s vote in the House on an omnibus budget bill will be yet another showdown between tea party conservatives and the outside groups which back them against the Republican establishment. The bill, based on the framework from the bipartisan Murray-Ryan budget deal in December, is being opposed by both Heritage Action and Club for Growth, two key players in the conservative movement. Both groups are key voting the bill, which means it will be used on congressional scorecards.

Heritage Action came out vehemently opposed to the bill. The group was deeply offended that the budget bill continued to fund Obamacare as well as frequent conservative hobbyhorses like the National Endowment for the Arts and National Endowment for the Humanities. The group detailed its complaints on its website, noting that omnibus also prevents the federal government from ending Saturday postal delivery as well as uses pays for specific local projects as well. It also expresses its discontent that the budget deal funds government programs that Heritage Action disapproves of like Head Start, Pell Grants and green energy.

In contrast, the Club for Growth was rather understated in its opposition. The conservative group issued a release stating “instead of finding bipartisan ways to spend more money, Congress should be focused on cutting spending so that the federal budget can be balanced as quickly as possible. This bill does not achieve that goal.” The statement was solely focused on spending levels under the omnibus and their increase over the sequester.

The opposition of these groups marks a new obstacle in efforts to smooth over the partisan divide on Capitol Hill. The budget deal has been hailed as a return to a slightly more normal state of affairs on Capitol Hill where there is “regular order” and the government is funded through the traditional appropriations process, not through continuing resolutions. The problem for these conservative groups is that in a divided government, this process means constant compromise between each party. In opposing the bill, both groups are planting their flag as part of the effort to try to avoid such compromises. The bill will likely pass anyway with significant Democratic support but the vote in the Republican caucus will provide yet another test of conservative strength in the House GOP.