LONDON (AP) — Litter has become a weapon of class war in Britain, where a call to "Clean for the Queen" has stirred both trash-tidying volunteers and howls of anger.

The campaign, backed by charity Keep Britain Tidy and corporate sponsors including McDonalds, is urging people to spruce up their communities before Queen Elizabeth II's 90th birthday, which is being marked in June. (Her actual birthday is April 21 — two birthdays a year are a royal perk).

"What better way could we show our gratitude to Her Majesty than to clean up our country?" the campaign asks on its Website.

A special litter-picking weekend kicked off Friday, with events scheduled across the country. Outside Parliament — one of the tidiest, most-photographed spots in the country — schoolgirls hunted valiantly for stray candy wrappers or coffee cups.

But some Britons felt insulted by the suggestion they should tidy up to honor a hereditary monarch who receives more than 35 million pounds ($50 million) a year from British taxpayers.

"I would rather swim in sewage than Clean for the Queen," ran the headline of a column by Michele Hanson in the left-leaning Guardian newspaper.

Graham Smith, chief executive of anti-monarchy group Republic, branded the campaign a "tacky PR exercise."

"I think a lot of people will literally ask, what has the Queen done for us?" he said. "Maybe she could put some of her fortune into cleaning the streets as a thank you for her years of privilege."

Britain has a serious litter problem. Keep Britain Tidy says more than 2 million pieces of trash are dropped on Britain's streets every day.

While some blame the litterbugs, others point out that garbage collection has been cut back in many areas as local government funding was slashed by the deficit-cutting central government.

Clean for the Queen organizers hope more than 1 million people will join in. Supporters hailed the campaign as an example of the volunteering "Big Society" touted by Prime Minister David Cameron.

In the conservative Daily Mail newspaper, commentator Toby Young slammed those who "prefer to sneer at efforts to tidy up Britain, rather than roll up their sleeves and get stuck in."

"Personally, I'm delighted to have the opportunity to do something for the queen, after the devoted service she's provided to this country, and I'm sure millions of others will be, too," he wrote.