Nurses, firefighters, teachers and prison officers joined an estimated 100,000 protesters on Saturday in huge demonstrations against the government, loudly cheering calls for a 24-hour general strike.

Union officials and politicians, including Labour leader Ed Miliband, bitterly attacked the coalition's spending cuts, accusing ministers of being more interested in supporting millionaires than ordinary workers.

The events in London, Glasgow and Belfast passed peacefully, although some disabled activists staged a sit-in and cut off traffic close to Hyde Park in London.

The Trade Union Congress said the turnout was better than expected and sent a strong message to the government about the unpopularity of its policies. General secretary Brendan Barber said: "We are sending a message that austerity is simply failing. The government is making life desperately hard for millions of people because of pay cuts for workers, while the rich are given tax cuts."

Barber said chief whip Andrew Mitchell's resignation and chancellor George Osborne traveling in a first class train carriage with a standard ticket showed how out of touch the government was.

He said: "The chancellor eventually paid for his ticket, but the rest of us are paying the price for his disastrous policies."

Protesters carried banners which read "Plebs against toffs", "Cameron has butchered Britain" and "24-hour general strike now" as they marched through Whitehall towards Hyde Park. They booed at Downing Street and shouted "pay your taxes" as they passed Starbucks.

Police officers stood outside the coffee shop, which has been involved in a row over its tax arrangements. Activists gathered outside a number of chain stores in central London, some wearing masks.

Dave Prentis, leader of Unison, said hundreds of thousands of public sector jobs were being lost as a result of government policies. "We are fighting for a better future. We are not here today for the millionaires - we are here for the millions of people who don't have a voice. We just can't take any more."

Unite leader Len McCluskey said millions were being pushed into poverty by a government more interested in supporting the country's elite.

The biggest cheers of the day came when Bob Crow, leader of the RMT rail union, and Mark Serwotka of the Public and Commercial Services union called for a general strike.

The TUC is consulting unions on the practicalities of a nationwide stoppage, although it will not be in time to take part in a Europe-wide day of action against austerity on 14 November.

Ed Miliband said the prime minister was clueless and was clinging to policies which were not working. Mr Miliband was booed by a small section of the crowd when he said Labour would have to make hard choices if it was in government.

He pledged that if he became prime minister he would tax bankers' bonuses, support the building of 100,000 houses and end the privatization of the National Health Service.