DENVER (AP) — Gov. John Hickenlooper cited concerns that children would lose coverage as he announced a veto Tuesday of a bill requiring some Colorado families to contribute more to a health insurance plan for low-income children.

The legislation would have increased costs for some families by 1,000 percent, forcing as many as 2,500 children to drop out, Hickenlooper said in a statement explaining his first veto of a bill.

“While the legislation was not intended to put children at risk, we have determined that the bill poses adverse consequences on children’s access to health insurance through the (Child Health Plan Plus) program,” Hickenlooper said.

Senate Bill 213 would have imposed monthly premiums on families based on their income.

Hickenlooper said he respects lawmakers’ intent to reduce the state’s share of rising health care costs, and his administration will explore other ways to cut costs.

The Colorado Children’s Campaign called the veto an important victory. The premiums would have made it tougher for families already struggling, said Chris Watney, the nonprofit group’s president and chief executive.

“Since 2000, Colorado has had the fastest growing rate of childhood poverty in the country and more than 120,000 Colorado kids are uninsured, putting them at risk for poor health outcomes and their families at risk for financial hardship,” Watney said.

Republican legislators criticized the Democratic governor’s veto, saying the bill was a bipartisan effort at welfare reform. It would have created a monthly premium for the families with the highest incomes, said Sen. Kent Lambert, R-Colorado Springs.

“It’s obvious that some of these parents have disposable income that is going into beer, cigarettes and lottery tickets,” Sen. Greg Brophy, R-Wray, told The Denver Post.