Washington (CNN) - With the clock ticking down until the U.S. hits its debt ceiling, conservative and progressive third-party interest groups whose pledges lawmakers have signed their names to are ratcheting up the pressure to keep them in line.

One of the biggest sticking points in negotiating a deal to raise the debt ceiling while addressing the long-term deficit has been Republican demands that there be corresponding dollar-for-dollar cuts in federal spending, that taxes cannot be increased to pay down the deficit, or that a balanced budget amendment is the only way to get the government on a path to longer-term fiscal health.