Congress is losing control over government spending because of a breakdown in the budget process, Senate Budget Committee chairman Mike Enzi warned Wednesday.

The Wyoming Republican delivered his comments in a hearing Wednesday on a new report finding that a majority of non-defense discretionary spending in fiscal year 2016, $310 billion, went to programs whose congressional authorization has expired.

"If we relinquish our responsibility to regularly review and reform these programs, all of our government funding will essentially operate on auto-pay," Enzi said. "This will prevent us from having the flexibility to support important priorities, or improve and eliminate government programs not delivering results."

The report, Enzi added, "only hints at the extent to which we're losing control of the annual spending," because it doesn't include spending on programs that were never authorized in the first place.

Congress both authorizes programs, a process that involves committees spelling out policies, and appropriates funds for them in a separate process. In recent years, however, Congress has increasingly appropriated funds for programs that have lost authorization.

While not illegal, appropriating funds for unauthorized programs raises the possibility that those programs are not receiving the oversight they should. Some of the programs in question are large, including the National Institutes of Health and the National Aeronautics and Space Administration, or NASA.

Witnesses at Wednesday's hearing testified that the rise of spending on authorized programs partly reflects growing polarization in Congress. For example, the Foreign Relations Authorization Act has not been reauthorized since 2003 because of disagreement over whether non-governmental organizations that provide or promote abortion should be given funds.

Because members of Congress can't agree on policy, spending ends up being determined in last-minute deals between congressional leaders and the White House.

Sen. Sheldon Whitehouse, D-R.I., said that these fiscal bargains involved "zero transparency."

Deals cut between party leaders are "as un-transparent as you can," Whitehouse said, "and things come in basically based on favoritism, clout, influence — it's kind of the worst of all possible worlds that we create for ourselves when there isn't a proper process and there's just a crisis negotiation at the end."

Some witnesses suggested changing the budget process to realign the incentives facing members of Congress to favor working on legislation that funds programs while ensuring they are overseen. Enzi and his counterpart in the House, Tom Price of Georgia, have expressed interest in overhauling the 1974 budget law that established the modern process.

James Thurber, a professor at American University, said that part of the problem is that members of Congress are forced to spend too much time fundraising versus doing their jobs overseeing the government.

"The extraordinary amount of time now spent away from Washington, D.C., and the work of Congress on fund raising by members in both bodies, undermines the capacity of Congress to make laws and do rigorous oversight," Thurber testified. He added that "the Tuesday to Thursday Club needs to be stopped with an enforceable required schedule of work in Washington."