DENVER – Amendments to a critical transportation funding bill Wednesday night trimmed a request from the state budget to $250 million a year and delayed the request for permission from voters until November 2019.

The Colorado Senate has been wrestling with Senate Bill 1 for a week. The legislation would tap the state budget ea each year to repay $3.5 billion in statewide transportation projects, but only after voters approve it. In the original bill Republicans sought $300 million annually, but it was an amendment from Democratic Sen. Rachel Zenzinger of Arvada that moved the vote back by a year.

Moving the referred ballot initiative to 2019, an off-year election, would cede a decision to ballot initiatives being planned for this November. The Denver Metro Chamber of Commerce is leading a statewide coalition that wants to ask for either .50 cents, .62 or a full penny to pay for transportation. An opposition ballot initiative led by the Independence Institute in Denver would force the legislature to pay for the improvements.

The bargaining in the Senate is an attempt to send the House a bill passed on a bipartisan vote. With a one-seat majority the Republicans could get it done by themselves. But in the House, the Democratic majority is hungry for more transit and hesitant to “mortgage” future budgets that still need to support schools and services in lean economic times.

The bill still has to pass a recorded vote in the Senate.

House Speaker Crisanta Duran of Denver told reporters Tuesday she wants a legislative solution, not one driver by outside interests. More amendments are likely before the bill makes it to a conference committee from both chambers to produce a compromise the House and Senate could vote on before their May 9 adjournment.

Democrats also want to ensure that transit projects get a fair share of any new money for transportation, which most Republicans oppose.

Sandra Hagen Solin of Fix Colorado Roads, a statewide coalition that has been driven much of the work on the issue for years, had reservations about the delay, an unexpected twist in months of negotiations.

“Happy to be moving along in the legislative process but a delay to 2019 is too long to wait for a solution,” she said.

There are under six weeks left in the four-month session now, and next week lawmakers in both chambers will be consumed with their heaviest lift each year, passing a balanced $30.5 billion state budget.

Gov. John Hickenlooper has asked for $500 million for transportation in this year’s budget and $150 million next year. Transportation advocates say that while that helps, they want an ongoing commitment from the state budget, not infusions during economic good times.

Colorado lawmakers are flush with cash this year because of a roaring economy and money generated by Republicans’ federal tax cut that will do away with deductions that are expected to generate more taxable income at the state level.

The Colorado Department of Transportation has estimated it needs $9 billion to catch up and keep up with growth over the next decade. Over the next 20 years – the life of the bonds – the state needs $20 billion for roads, bridges and transit.