updated 4:48 p.m. ET July 28, 2009

WASHINGTON - The four major pro sports leagues and the NCAA are asking a federal judge for a preliminary injunction to prevent Delaware from implementing sports betting.

The motion was filed Tuesday in federal court in Delaware. Last week, the leagues filed a lawsuit against the state, arguing that the state’s plan for sports betting violated federal law.

Congress banned sports betting in 1992 while allowing it in four states — Delaware, Nevada, Montana and Oregon — that had already been offering it.

The lawsuit argues that Delaware’s plan to allow single-game betting would violate the legislation because Delaware has never offered single-game betting before.