A suit brought by two workers against the IRS’s maximum paycheck withholding rule should be dismissed for seeking to enjoin tax collection, the US government told a Texas federal court.

Matthew Lobdell and Shawn Gibson sued last month in the US District Court for the Northern District of Texas, targeting a Treasury regulation that allows the IRS to issue “lock-in letters” directing employers to ignore employee tax withholding forms and withhold maximum taxes from paychecks. The request is barred by the Anti-Injunction Act because it would functionally block tax collection, federal authorities said in a Wednesday brief opposing the plaintiffs’ …