CHICAGO (Reuters) - Abortion opponents in Illinois filed a lawsuit on Thursday to block a recently approved law expanding state-funded coverage of abortions for low-income Medicaid recipients and state workers.

The lawsuit was filed in Sangamon County Circuit Court on behalf of taxpayers by the conservative Thomas More Society, along with some state lawmakers and anti-abortion groups.

It asked a judge to block state funding for the law, arguing that the state failed to set aside up to $30 million in the budget to pay for abortions. The lawsuit also argued that the law could not take effect until June 2018, instead of January, because of when it was approved.

“The people of Illinois are opposed to taxpayer funded abortion, especially with the terrible financial state that Illinois is in,” Peter Breen, a Republican state lawmaker and an attorney for the Thomas More Society, said on Thursday.

He argued that the state would have to pay for up to 30,000 abortions a year.

Illinois Republican Governor Bruce Rauner signed the bill in September, upsetting many conservatives.

“I do not think it’s fair to deny poor women the choice that wealthy women have,” Rauner said at the time.

The American Civil Liberties Union of Illinois supported the law, saying it would keep women from being denied abortion coverage just because they were on Medicaid or worked for the state. Medicaid is a government healthcare program for the poor and disabled.

Ed Yohnka, the ACLU’s director of public policy and communications, on Thursday rejected the lawsuit’s contention that lawmakers needed to designate specific funds.

“That’s like saying the General Assembly has to appropriate money for knee replacements,” he said.

About 15 other states allow Medicaid to pay for abortion, including some required by courts, according to the Kaiser Family Foundation. Illinois was the first state in decades to voluntarily lift a restriction on such services.

Illinois’ Medicaid program has previously covered abortions in cases of rape, incest and when a mother’s life or health is threatened.

The expansion would enable poor women to obtain elective abortions. The law would also allow state employees to have the procedures covered under state health insurance.

The law’s passage by the Democratic-controlled Illinois legislature came after some other U.S. states, which are controlled by Republicans, have sought in recent years to tighten regulations on abortion clinics and forced closures in Texas and Kentucky.