Two professional sports leagues are seeking a cut of New Jersey's sports betting revenue if the U.S. Supreme Court allows the state to legalize it -- but top lawmakers aren't playing ball, NJ Advance Media has learned.

The National Basketball Association and Major League Baseball have long fought New Jersey's effort to legalize sports betting, filing lawsuits alongside the National Football Leagues, the National Hockey League, and the National Collegiate Athletic Association to stop it.

But now, the NBA and MLB are asking states across the U.S. to allow them a percentage of the total amount wagered on their games should the nation's highest court side rule in favor of New Jersey and overturn a 26-year-old ban on sports betting in all but four states.

The court could issue a ruling as early as next week.

The leagues say the fee is part of a broader effort to protect the integrity of their sports and prevent cheating and game-fixing. Plus, they say, they deserve compensation for providing the games on which the bets are made.

Representatives for the NBA and MLB have met privately with New Jersey's leaders in recent months to prepare.

Lobbying records released Tuesday show they've met with Peter Cammarano, Gov. Phil Murphy's chief of staff, as well as state Senate President Stephen Sweeney, D-Gloucester, and state Assembly Speaker Craig Coughlin, D-Middlesex. The meetings were first reported by Politico New Jersey.

But legislative leaders have balked at the leagues' request for a fee, three sources with knowledge of the situation told NJ Advance Media. One source called the proposal "laughable."

The leagues first asked for a 1 percent cut but are now willing to negotiate to a lower number, according to a person with direct knowledge of the leagues' thinking. They have negotiated to 0.25 percent in several other states.

The sources asked for anonymity because they did not want to publicly discuss sensitive conversations.

New Jersey leaders aren't happy the leagues are asking for a cut when Las Vegas -- where sports wagering is allowed -- gives no revenue, sources said. They are also not pleased that the leagues want a say in how the state writes regulations now that it seems like they may lose a court battle that has cost New Jersey $9 million.

Representatives for Murphy, Sweeney and Coughlin declined to comment.

Former state Sen. Raymond Lesniak, a Union County Democrat who led the fight for sports wagering in New Jersey, told NJ Advance Media the leagues are "a day late and a dollar short."

"Now that we're on brink of a victory, they com looking for a piece of the action?" Lesniak said Thursday.

Despite their lawsuits, the leagues' views on sports betting have changed in recent years. NBA Commissioner Adam Silver has said it should be legalized and MLB Commissioner Rob Manfred has said it could boost fan interest in his sport.

The NFL is still opposed, but Commissioner Roger Goddell has said his position has "evolved."

The NFL, NHL, and NCAA are not involved in the NBA and MLB's lobbying efforts.

The two leagues are asking sports betting states for a few things, including consumer protections, mobile access, promises that casinos across the country will use the same statistics and data to prevent fraud, and allowing the leagues to restrict certain bet types susceptible to fraud. The fee is another part.

"Sports betting is a very real possibility, and we have an obligation to our fans and our sport to provide our perspective in order to ensure the integrity of our games is protected, as the damage from even a hint of scandal will hurt the sports leagues far worse than anyone else," Major League Baseball said in a statement.

The league added that it's reasonable to compensate the leagues for "the real risk to reputation" that comes with sports betting, the fact that there would be no wagering without the leagues' games, and the expense the leagues "will incur to rigorously police integrity."

Lesniak said New Jersey doesn't need the leagues to make sure the betting is credible.

"We can have our own officials do that," he said.

The gaming industry is also opposed to the fees. William Hill sports book CEO Joe Asher says it actually equals 20 percent of sports book revenues because sports books generally take only 5 percent of the total amount wagered.

So far, four other states have passed sports betting laws in anticipation of the Supreme Court's ruling: Mississippi, New York, Pennsylvania, and West Virginia. And 14 other states are considering such legislation.

Illinois and Indiana have included the 1 percent fee in their bills. There are measures in Connecticut, Kansas, Missouri, and New York with a 0.25 percent fee.

Daniel Wallach, a sports gaming expert, said that despite losing six previous decisions in the case, New Jersey "has never been in a better place in the federal court than it is today."

"The script has been flipped," said Wallach, a gaming and sports law attorney with Becker & Poliakoff in Fort Lauderdale, Florida. "The question becomes: What will victory look like?"

Wallach said there are two scenarios if New Jersey wins: The court will either overturn the ban completely or simply allow New Jersey to implement its law allowing sports betting at casinos and tracks without state regulation.

Either way, Wallach said, New Jersey will have a head start on other states. He said none of the others that have passed legislation are ready to go yet.

Monmouth Park in Oceanport has already constructed a sports betting parlor that owners say will be ready to go within weeks of the ruling.

No decision released on Supreme Court sports betting case today, but Monmouth Park in New Jersey is still getting ready. Put up 42 screens by where they would accept bets if decision goes their way. pic.twitter.com/FRqNEjKw07 — Darren Rovell (@darrenrovell) April 17, 2018

"I'm optimistic," the new governor said during an event Wednesday.

The Associated Press contributed to this report.

Brent Johnson may be reached at bjohnson@njadvancemedia.com. Follow him on Twitter @johnsb01. Find NJ.com Politics on Facebook.