PHOENIX — In an effort to save the Medicaid expansion program, a bipartisan coalition of lawmakers, business groups and even a former governor want the Arizona Supreme Court to block a bid by dissident legislators to challenge its legality.

In legal papers filed Tuesday, attorney Joe Kanefield told the justices there is no reason to allow the lawmakers who voted against expansion — and the tax to fund it — to argue it was never properly approved. He said only the hospitals subject to the levy have a right to contest the fact it was enacted without a two-thirds vote.

The hospitals, however, have not sued as they stand to financially benefit, even after paying the levy, because an expanded Medicaid program means fewer patients unable to pay their bills.

Kanefield said the hospitals’ decision not to sue does not give legislative foes the right to challenge the levy.

Hanging in the balance is more than just the estimated $256 million the levy is expected to raise this year.

Without those funds to qualify for federal dollars, the entire expansion plan pushed through by Gov. Jan Brewer would collapse. And the state would have to stop providing health care to the more than 300,000 Arizonans who were just added in January.

The levy was approved last year by a majority of lawmakers — a bipartisan coalition of mostly Democrats in the Republican-controlled House and Senate.

Legislative foes sued, saying the levy is a tax, which constitutionally requires a two-thirds vote. A trial judge threw out the challenge, saying the legislators have no legal standing.

But the Court of Appeals ruled in April that the argument ignores the constitutional requirement. And it said the minority bloc of legislators who voted against the tax — there were enough to block a two-thirds margin — had the right to challenge the procedure used to approve it with a simple majority.

The Supreme Court is set to consider Brewer’s appeal of that ruling on Aug. 27.

In his court filing Tuesday, Kanefield said the dissident lawmakers have no legal standing to challenge the failure to get a two-thirds vote.

“Here, the purpose of (the constitutional provision) is to protect those who pay non-exempt taxes and fees from increases in the amount they must pay,” he wrote. And Kanefield said the challenging lawmakers are not affected by the levy.

Kanefield used to be the governor’s personal legal counsel. But he said his clients are the lawmakers who support the levy and the business groups that want an expanded Medicaid program, and that the lawsuit is not being paid for with state dollars.

Also signing on to defend the levy against challenges is former Republican Gov. Fife Symington. He did not immediately return calls asking about his interest in this issue.