PHOENIX — In a major reversal, the Glendale City Council voted Tuesday to oppose federal legislation designed to block a tribal casino on the city’s west side.

The 4-3 vote does not end Glendale’s opposition to plans by the Tohono O’odham Nation to build a $550 million retail and hotel complex on the west edge of the city anchored by a casino. And various federal court lawsuits by the city to halt the project remain active.

But the move could pave the way for a deal between the tribe and the city, potentially one that might even lead to a revenue-sharing agreement.

The council vote apparently caught the other tribes by surprise. Within hours, the Salt River Pima-Maricopa Indian Community sent out a press release pointing out how many area mayors not only want the casino halted but support HR 1410, which is making its way through Congress.

But the new Glendale council vote could take the wind out of that measure, which is awaiting Senate action. And that could dim the chances for those other area tribes to block the Glendale casino, which could cut into their own gaming business.

Using a 1986 law to compensate for lands flooded by a federal dam project, the Tohono O’odham bought the property more than a decade ago. But plans for a casino were not made public until 2009.

The tribe now is moving to have the land made part of its reservation, a legal precursor to gambling operations. So far various lawsuits to block that have faltered.

HR 1410, sponsored by Republican U.S. Rep. Trent Franks of Glendale, would retroactively amend that 1986 law to preclude any gambling operations on the site until at least 2027, effectively killing the casino plans. He already has shepherded the measure through the House, though its fate in the Senate remains uncertain.

With little luck blocking the casino in court, the council voted last November to at least open talks with the tribe. Tuesday’s council work session was to get an update on that.

But what also happened was the council deciding, on that split vote, to back away from Franks’ legislation.

Councilman Gary Sherwood, who cast the deciding vote, said it could be seen as an “olive branch” of sorts designed to push toward a final resolution of the battle he said already has consumed $3 million in legal fees for the city.

But Sherwood said he also concluded that HR 1410 did not make long-term sense for the city. He said blocking a casino on the site would not mean the tribe would do something else with the property.

“They could just sit on it until 2027,” he said, meaning a large undeveloped parcel very close to the entertainment district the city has built surrounding the Arizona Cardinals’ stadium.

That’s also the assessment of Councilman Ian Hugh. “It’s just a pile of dirt,” he said. “We want that land to develop.”

Tohono O’odham Tribal Chairman Ned Norris Jr. said the tribe looks hopes to “find a way for us to move forward together for the benefit of the entire West Valley.”