The American Civil Liberties Union and the ACLU of Michigan filed a federal lawsuit Thursday against a new state law that eliminates health care coverage for the domestic partners of public employees.

The lawsuit charges that the new law discriminates against gay and lesbian public employees by forcing them to carry the financial hardship and anxiety of having an uninsured partner. Heterosexual couples can marry and receive family health protections, but same sex couples cannot. Same sex marriage and civil unions in the state were banned by a constitutional amendment in 2004.

“Although justified by the governor as a cost-cutting measure, the numbers don’t hold up,” said Kary L. Moss, executive director of the ACLU of Michigan. “The reality is that the legislation was intended to disenfranchise LGBT families. When a key policy priority has been to attract top talent and resources to the state, our elected officials have sent a clear message that Michigan is out of step with the kinds of public policies that attract talent and grow our economy.”

Supporters of the law said domestic partner benefits only cost the state about $840,000. $8 million. But opponents of the law, citing the Michigan Civil Service Commission, put that figure much lower, at about $840,000.

“It’s unconstitutional for the state of Michigan to deprive a small number of workers the means to take care of their loved ones when other similarly situated workers do have access to family coverage,” said Amanda C. Goad, staff attorney for the ACLU LGBT Project.

“In an economic downturn, the state should be passing laws to make it easier for families to take care of each other, not to take protections away.”