At one central London outlet activists from the anti-austerity UK Uncut movement staged a sit-in, chanting "Starbucks pay your taxes" and briefly setting up a children's crèche before police moved them on.

Protests were held at more than 40 of the multinational's cafes, including in Liverpool, Birmingham and Cardiff, UK Uncut said. The demonstrations were held two days after Starbucks said it would pay around 20 million pounds ($32 million) in British corporation tax over the next two years.

Its announcement came after weeks of criticism in the media and parliament following a Reuters report which said Starbucks had paid no corporation tax in Britain over the past three years while telling investors the local business was highly profitable.

Starbucks' tax offer was just a "massive PR stunt", said Rosie Rogers, a 26-year-old UK Uncut activist, outside one of the chain's London restaurants.

"If Starbucks, if all the tax avoiders, paid their fair share, 25 billion pounds could be put back into public services and enrich our economy," she said.

At a nearby Starbucks cafe protesting women lay down in sleeping bags in a symbolic transformation of the outlet into a women's refuge, a service they say has been hit by state spending cuts.

Finance minister George Osborne said on Wednesday his plan to rid Britain of a record deficit would take even longer than expected, extending the shrinking of state spending another year to 2018.

Ahead of the protests Starbucks appealed directly to its customers in newspapers adverts reprinting its pledge to pay corporation tax in Britain.

"We know we are not perfect. But we have listened ... We hope that over time, through our actions and our contribution, you will give us an opportunity to build on your trust and custom," UK managing director Kris Engskov said in the adverts.

The company says it has always acted legally since opening in Britain in 1998 and is not hiding big profits from tax authorities. Despite serving 2 million British customers a week the firm says high rents for its prime location cafes have made it hard to turn a profit.

(Writing by Tim Castle; Editing by Stephen Powell)

• A Permanent Economic Emergency