The Republican Party of Texas is suing Houston Mayor Sylvester Turner and others involved with the canceling of the party's in-person convention, which was scheduled to happen next week.

On Wednesday, Houston First Corporation, the operator of the George R. Brown Convention Center, sent a letter to party officials informing them that the event had been canceled. That cancellation happened after Turner announced he was directing the city's legal department to work with Houston First to review the contract for the event.

The lawsuit, filed Thursday in Harris County, argues that the gathering is protected under both the Texas and U.S. Constitutions and should be allowed to continue as planned.

"Mayor Turner may not treat the [Republican Party of Texas] convention differently from that of the recent public protests that the Mayor supported," reads the petition, which also lists Houston First and the city of Houston as defendants. "Political viewpoint cannot be the basis for unequal treatment."

The party's biennial convention was expected to draw roughly 6,000 people to a city that is a hotspot for the coronavirus. Republican leaders had planned to deliver their speeches via video, which the party's executive director said would enable them to "get everybody in and out of here as quickly and as safely as possible."

Turner, asked about the lawsuit at a news conference later Thursday, said the party signed the contract in March with a force majeure clause that included epidemics in Houston. That clause allows either party to cancel the agreement if an occurrence "is beyond the reasonable control of the party whose performance is affected," according to the letter Houston First sent to the party Wednesday.

"It's ironic that they're going to the courthouse ... to ask them to agree to allow 6,000 people to meet in-person when even the judicial community is hearing cases virtually," Turner said.

In its lawsuit, the party agued that the mayor and Houston could in fact "perform if they wished, but they simply did not want to" and that Turner's instruction to his legal department to examine the contract counted as an admission thereof. "The admission means that he cannot use force majeure as a magical spell to escape what he has decided is an unwanted contract," the petition reads.

The party is also seeking damages "regarding the anticipatory breach" of the contract, including financial losses related to deposits, "increased costs of handling the Convention elsewhere" and "expectancy damages" for funds that would have ordinarily been raised at the event.

State Rep. Briscoe Cain, R-Deer Park, and Warren Norred, a State Republican Executive Committee (SREC) member, are representing the party in its lawsuit. The SREC, a 64-member body that serves as the governing board to the state party, voted overwhelmingly last week to proceed with an in-person convention, despite calls to cancel it.

This is the second lawsuit related to the cancelation filed on Thursday. Earlier, a handful of other Republicans including Houston activist Steve Hotze and Texas GOP secretary Josh Flynn, sued Turner, the city and Houston First.

Party officials have worked on a contingency plan to host the convention online, though it is unclear whether the party will end up taking that avenue or moving the convention to another location where it can be held in-person. On Wednesday, Montgomery County Judge Mark Keough offered the party to host its convention there, saying in a video that the county "is open for business."

This post has been updated.