OLYMPIA — An attempt to block a statewide vote on expanded benefits for domestic partners is back in court Tuesday in Olympia.

Thurston County Superior Court Judge Thomas McPhee will hear arguments in a lawsuit brought by a group called Washington Families Standing Together. The group claims that Secretary of State Sam Reed improperly accepted thousands of petition signatures. Reed disagrees, and the state is defending his agency.

The referendum’s sponsor, a group called Protect Marriage Washington, wants a public vote on the “everything but marriage” law, in hope of overturning broader domestic partnership benefits for gay couples.

The law also would extend marriage-like benefits to unmarried heterosexual couples over the age of 62.