New York City must turn over written communications between the mayor’s office and the Rent Guidelines Board in a lawsuit over this year’s rent freeze.

A judge ordered the disclosure of messages exchanged from Jan. 1 through June 25 as landlords seek to overturn the board’s June vote to freeze rents for one- and two-year rent-stabilized leases signed on or after Oct. 1.

The challenge centers on whether the board acted independently. The lawsuit argues that the decision was influenced by Mayor Zohran Mamdani, who had pledged during his campaign to freeze rents if elected. The freeze applies to about 1 million rent-stabilized apartments across the city.

Landlords are asking the court to void the freeze, send the matter back to the board for a new vote and require a rent increase instead. In ordering discovery, Judge Brendan T. Lantry said the allegations had raised concerns about the lawfulness of the board’s voting process.