LANSING (AP) — Michigan Republicans’ maneuver to weaken voter-proposed laws to raise the minimum wage and require paid sick leave was “outright unconstitutional,” a top appellate lawyer said Wednesday while urging the state Supreme Court to stand as a “last line of defense” against the unprecedented tactic.

An attorney for the GOP-led House and Senate countered that nothing in the state constitution prevents the Legislature from amending a citizen-initiated law at any time, including during the same legislative session.

At issue is “adopt and amend,” a strategy that majority Republicans used last year. To prevent minimum wage and sick time ballot drives from going to the electorate in November, after which they would have been much harder to change if voters had passed them, GOP legislators approved them in September so that they could be made more business-friendly after the election with simple majority votes and the signature of the outgoing Republican governor, Rick Snyder.

Solicitor General Fadwa Hammoud, who is with Democratic Attorney General Dana Nessel’s office, said the maneuver killed voters’ right to petition lawmakers, thwarting their will.

“This was outright unconstitutional. It was a slap in the face to the people that reserved their rights to themselves and it basically nullified that provision of our constitution in every way,” said Hammoud, who was one of five lawyers to speak during more than 100 minutes of arguments. “This court has been the last line of defense when it came to the Legislature intruding on the people’s voice.”

The high court is considering legislators’ request for a rare advisory opinion on the constitutionality of the tactic, which could potentially avoid a lengthy legal fight.

Under the Michigan Constitution, a group can collect hundreds of thousands of voter signatures to qualify an initiated bill for a November ballot. Legislators then have a 40-day window in which they can enact it, reject it — putting it to a statewide vote — or propose an alternative to appear alongside the measure on the ballot.