(CBS) — Illinois lawmakers will consider landmark legislation to resolve the states $100 billion pension crisis Tuesday in Springfield. But, it won’t be an easy vote, reports WBBM Political Editor Craig Dellimore.

In the proposed deal, state workers currently under age 46 will retire later. In exchange, employees will contribute 1 percent less to their pensions. But retirees annual cost of living increase will also be lower, eventually switching from a compounded increase to one based on the consumer price index.

“The essence of the compromise is the House got what it want on total cost savings, the Senate got what it wanted in terms of the inflation adjuster for people that will benefit under these pensions systems,” said Illinois Speaker Michael Madigan.

The four legislative leaders and Governor Quinn back the pension bill, but Republican State Treasurer Dan Rutherford who is running for governor says he opposes the pension deal, saying it is unconstitutional.

Republican rival Bruce Rauner suggests it is a backroom deal and Kirk Dillard says more time is needed to study it.

But Democratic Representative Elaine Nekritz, one of the architects of the bill, says lawmakers have debated every element of the legislation.

“A lot of the push-back in terms of ‘Oh, we haven’t read the bill’ or ‘It doesn’t go far enough,’ is really politically motivated rather than being motivated by a desire to solve a problem on behalf of Illinois,” said Nekritz.

As for constitutionality, she says the courts can decide that. The unions will challenge it regardless.

“This is stealing the life savings of retired teachers and police, nurses and caregivers,” said Anders Lindall with the AFSME.

The plan would ensure the pension system is fully funded by 2044.

Governor Quinn plans on coming to Springfield Monday night to talk to lawmakers about the deal, which he is calling the most important fiscal vote lawmakers will ever take.