‘Does it look big?’ an elderly woman asked me, craning her neck to see down the street. ‘I’m afraid so,’ I replied, thinking she might be worried about getting to the Tube. ‘Good,’ she said. Like thousands of others, she was in London on Saturday for the national anti-austerity demonstration organised by the People’s Assembly.

As we marched from the Bank of England to Parliament Square, the crowd kept growing. The protesters, representing movements including Quakers for Justice and the Association of Child Psychotherapists, came from all over Britain: transport was provided by local People's Assembly groups and trade union branches. A group from Penzance, with a black banner and a little pirate in tow, said they’d had to start at 3 a.m., but 'it was all right, we managed to sleep on the coach'.

A man in white overalls had 'Chefs against austerity' written on his hat; another, all in yellow, had 'Grumpy old git against fracking' on his T-shirt. Other slogans included: 'Austerity: economically illiterate + morally abhorrent'; 'Stop the NHS becoming a skeleton service'; 'Cats not cuts'. There were Green Party supporters and other eco-campaigners; one leaflet claimed that 'veganism is the Swiss army knife of the future.’ A group protesting against the Transatlantic Trade and Investment Partnership dressed in yellow and black stripes because the agreement (which includes pesticide deregulation) threatens bees as well as so much else.

Familiar chants – 'Labour, Tory, same old story'; 'No ifs, no buts, no public sector cuts' – alternated with new ones: 'David Cameron, get out! We know what you're all about: cuts, job losses,money for the bosses.' A girl with a phone number written on her shoulder said it was a precaution in case she got arrested; some demonstrators hid their faces under black scarves or masks. A man in a toy police helmet introduced himself as a 'police liaison liaison officer'.

A bus tour operator was stationed in Whitehall (packed and closed to traffic) to inform potential customers that there would be no buses on that route (there were bus drivers marching with the RMT bloc). A hundred yards down the road, socialists agitated for a 24-hour general strike on 8 July, when George Osborne will deliver a new budget with planned welfare spending cuts of £12 billion.

An estimated 50,000 people gathered in and around Parliament Square. 'We are here to remind the government that 76 per cent of people did not vote for them,’ Caroline Lucas, the Green MP, said. 'David Cameron thinks... he can do whatever he wants to us over the next five years without opposition,’ Sam Fairbairn of the People's Assembly said. ‘He's wrong: we are that opposition.’ The singer Charlotte Church condemned politicians for 'selling out democracy'. The Labour leadership candidate Jeremy Corbyn talked about housing and private sector regulation, immigrants and refugees. 'It is possible to have a different world,' he said, one in which there were no unnecessary austerity measures or 'ghastly inequality on an industrial scale': 'I think it's called socialism.'