Antiwar groups planning to protest during the Republican National Convention in St. Paul have sharpened their argument with city officials.

They filed a memorandum in U.S. District Court on Monday aimed at persuading a judge to issue a preliminary injunction later this month to force the city to set a route for a demonstration on Sept. 1, the first day of the convention.

"With less than 16 short weeks until the convention begins, the First Amendment cannot be told to wait further on the City of St. Paul," the memo said.

A lawsuit filed by the protesters accuses city officials of violating their free speech rights, saying the officials have so far frustrated their efforts to obtain a march route permit from the State Capitol to Xcel Energy Center and back.

City officials have defended their handling of the protesters' permit application and have said they will approve a route no later than May 31, although they reserve the right to revise the guidelines and permits if necessary.

The protesters argue that potential administrative delays and possible additional court challenges could run out the clock, giving them too little time to prevail in court should they be dissatisfied with the route or conditions of the permit. That, they said in the memo, is what happened in the run-up to the Democratic convention held in Boston in 2004. Protesters there complained that they were kept too far away from the convention site to have an impact.

Protesters applied for a permit more than a year ago but were turned down because city officials said a city ordinance mandates that permits be issued no more than six months in advance.

In their memo, the protesters argue that they need time to find financial underwriters for their protest, publicize it widely "and assure would-be protesters that St. Paul will treat them fairly."

A hearing on the matter is set for May 16.