Minnesota lawmakers on Monday began the hard work of eliminating the state’s $1 billion budget deficit, approving bills that tackle one-third of the problem.

The House and Senate, both controlled by Democrats, passed separate bills that cut more than $300 million in state spending. In the process, they swept aside Republican Gov. Tim Pawlenty’s recommendations for the same spending categories.

Lawmakers have said they will address the remainder of the deficit in two additional budget bills, but after years of making cuts, they said it’s getting harder to take another whack.

“We have some tough decisions to make this legislative session. This is the first of three that will be coming forward,” said Rep. Lyn Carlson, DFL-Crystal. “We do have a constitutional requirement to have a balanced budget.”

The Legislature’s first cuts affect colleges, prisons, courts, agriculture and natural resource programs and local government allowances. The two chambers plan to merge their bills and send the combination to Pawlenty before the end of March.

Lawmakers rejected Pawlenty’s proposals for spending cuts in the same areas. His plan garnered a mere 15 votes out of a possible 201, with most Republicans joining Democrats in opposing the governor’s recommendations.

Pawlenty will consider the Legislature’s budget bills, but he would prefer they make all their cuts at once so he could look at their entire plan, said his spokesman, Brian McClung.

The House and Senate bills trim far less money from payments to local governments and colleges than Pawlenty proposed. The Senate proposal cuts deeper than the others into the agency that runs state prisons. Both legislative plans count on $25 million from a fee increase related to mutual funds and securities sold in the state.

Cuts included in the bills are as small as a $14,000 reduction to a native grass research program and as large as a $105 million whack at payments local governments use to hold down property taxes.

A small number of programs would receive more money. For instance, $100,000 more is set aside to help pay for honor guards at veterans’ funerals. Almost $7 million would go into compliance efforts to get tax delinquents to pay up, expected to yield $20 million in the end.

The House also approved an amendment that would require state agencies to scrutinize their spending by scrapping their budgets and starting anew every two years.

The bills don’t touch the two biggest areas of the Minnesota budget: public health and welfare programs and money for kindergarten through high school. Cuts to those areas, if needed, will be addressed in future bills.

The billion-dollar shortfall covers the next 14 months. Any solution will be temporary because economists predict a deficit several times as big for the next two-year budget period, which begins in July 2011.

“We have deficits out as far as our eye can see,” said Rep. Jenifer Loon, R-Eden Prairie, who argued for a more aggressive approach to reviewing state agencies and government programs. “We’ve got to take steps to break the mold, tear apart those structures and start over again.”