A bill to let children of undocumented immigrants in Colorado pay tuition rates lower than out-of-state students is staying in the state Senate for another week while supporters try to line up more Republican support for a full-scale push in the GOP-led House.

The legislation, Senate Bill 15, sponsored by Democratic Sens. Angela Giron of Pueblo and Michael Johnston of Denver, received preliminary approval from the Democratic-controlled Senate on Friday but needs another vote before it can proceed to the Republican-led House.

That was expected to occur Monday, but Senate Democrats tabled the vote for a week while they gird for a tougher battle in the House.

Johnston said supporters are trying to get all of Colorado's major institutions of higher learning to endorse the bill, which most have done already. In addition, though, Johnston said proponents are trying to get more GOP heavy-hitters to encourage House Republicans to support the bill.

Several prominent Republicans, including Alex Cranberg, chairman of Aspect Energy, have long-supported lowering tuition costs for undocumented immigrants, who -- if charged the out-of-state rate -- have to pay two to four times as much as in-state students, making college out of reach for many.

"I think that's what's encouraging us, is we have bipartisan support for the bill," Johnston said.

With Republicans holding a 33-32 majority in the House, and with one Republican already indicating he will vote for the bill, the question now is which committee will get the bill. House Speaker Frank McNulty, R-Highlands Ranch, has said the House Education Committee, where the bill likely would pass, may not get the bill, but he hasn't said what other committee might get it.

The bill creates a category of tuition higher than in-state tuition but lower than out-of-state. For example, while an in-state student at the University of Colorado-Boulder would pay $9,152 for 30 hours of credit, an undocumented immigrant would pay $11,012 for the same number of hours.

An out-of-state student, however, would pay $30,330 per year in tuition.