Delegates to the Republican convention, which begins in Madison Square Garden on Monday, will face opponents releasing swarms of mice, posing as volunteers to send old ladies in the wrong direction and hiring sex workers with Aids to seduce them, according to a columnist on the New Hampshire Sunday News, Bernadette Malone.

Meanwhile Rupert Murdoch's New York Post is warning that "people trained in kidnapping techniques, bombmaking and improvised munitions" will orchestrate operations.

It adds: "A number of extremists with ties to the 1970s radical Weather Underground are preparing to wreak havoc."

A poll by the New York Times yesterday found that more than half of New Yorkers were "very" or "somewhat" worried that there would be a terrorist attack during the week.

The city, which is overwhelmingly Democratic, has launched a campaign to "make nice". The mayor, Michael Bloomberg, has offered discounts at Broadway shows and restaurants to those wearing a badge proclaiming "peaceful protester".

Ms Malone is not impressed. "By wearing these buttons and obtaining these nifty little discounts, the mice-releasers, pie-throwers and Aids-spreaders are entering into an implicit agreement with the rest of society," she says - "give me $5 off a chicken entree at Applebee's and I promise not to terrorise you."

"Perhaps the Department of Homeland Security should hand out buttons that say 'Peaceful Islamic Radical'. All the scary-looking guys with fertiliser on their shoes and wires coming out of their pockets can enjoy nice-priced margaritas and reduced admission live sex shows before they blow up Madison Square Garden."