WASHINGTON - Congressional Democrats are pushing what could become the most dramatic expansion of college aid for military veterans since World War II, with a bill they hope will buoy them this election season and become an albatross for Republicans.

The plan would essentially guarantee a full-ride scholarship to any in-state public university, along with a monthly housing stipend, for individuals who serve in the military for at least three years.

The proposal would give veterans 15 years to use the benefit, instead of the current 10-year limit, and would set up a new government program that matches financial aid by more expensive private institutions.

For a pricey public school -- such as Miami University in Oxford, Ohio -- that benefit might be worth as much as $31,000 per school year, compared with the $9,900 average benefit that veterans are given now.

"Meeting the needs of our veterans is a cost of war," said House Speaker Nancy Pelosi, D-Calif., who described the bill as a "thank you" to the troops serving in Iraq and Afghanistan.

While Democratic leaders say they see a yes vote on their proposal as an obvious move for any lawmaker facing voters this fall, the new GI benefits plan has Republicans -- and even some members of the more fiscally conservative Democratic rank-and-file -- balking at the cost.

The nonpartisan Congressional Budget Office estimates that the proposal would cost $51.8 billion in the next 10 years.

The Pentagon has said that it's open to boosting college aid, even substantially, for veterans but wants the commitment to the military to extend to at least six years, instead of three, before the full benefit kicks in.

"The last thing we want to do is create a situation in which we are losing our men and women who we have worked so hard to train," Pentagon spokesman Geoff Morrell said.

Republican Sens. John McCain of Arizona, Lindsey Graham of South Carolina and Richard Burr of North Carolina have proposed an alternative that would boost the maximum monthly stipend for GIs from $1,100 a month to $1,500 a month.

A House vote is planned this week.

AT A GLANCE

Examples of benefits under the current Montgomery GI bill:

* Active-duty members who have continuously served for at least two years and forfeit $1,200 of their pay in one year, are entitled to receive $1,101 a month as a full-time student for up to 36 months, which is equivalent to four academic years.

* In general, the benefit must be used within 10 years of leaving the service.

* Part-time students receive less but can stretch the benefit over a longer time.

* Some service members can increase their buy-in to the program by contributing more each month. Boosting their mandatory annual payment from $100 a month to $600 a month, for example, can make them eligible to receive up to an additional $5,400 in college aid.

Examples of benefits under the proposed GI bill:

* Troops would no longer have to forfeit any of their pay to receive the benefit after they leave the service.

* Instead of receiving a fixed monthly stipend, veterans who have served three years or more would be reimbursed the tuition costs of any public school in their home state.

* More specifically, the program would cover tuition "up to" the state's most expensive public school, $1,000 a year for books and fees, and any costs incurred from tutoring or to take certification or license tests. An average $1,000 monthly stipend also would be given for housing costs.

* The benefit must be used within 15 years of leaving the service.