Welcome to live coverage of the marches taking place across the UK against the government's austerity measures. The events have been organised by the TUC, which says the policies are harming the economy. The largest march takes place in central London and starts from the Embankment at noon. Protests in Glasgow and Belfast have already begun.
Here's the scene on the Embankment when TUC general secretary Brendan Barber and other union leaders gathered for the start of the march, which is now under way.
The trade unions were among the first to suggest that the government's austerity plans would harm the economy. The marches are intended to demonstrate that the opposition is now much more widespread. Anti-war campaigners, politicians and activists are also taking part. Mr Barber says the marchers want to tell the government that austerity is not working. "This is a government of broken promises," he told the BBC earlier. "They told us we were on our way to a recovery and instead we've been mired in a recession."
Campaign group the Taxpayers' Alliance, however, has offered an alternative take. Its chief executive, Matthew Sinclair, says the cuts were needed. He says the marchers will not "make any difference to the simple arithmetic that the government is spending a lot more than it can afford to, that the government is living beyond taxpayers' means... I think that if the unions think that that is an argument they can still win, I think they are just deluded."
There's more background to the march and the austerity cuts in our news story, which is also being updated with the latest information from the protests.
1227 Richard Lister, BBC News correspondent
says the front of the march is now passing Big Ben, with plenty of banners and large red Unite balloons in sight. There are whistles, drums and horns with the crowd "lively" and the atmosphere "good natured".
Campaign group UK Uncut are also taking part in the march. Spokeswoman Sarah Miller says: "The cuts are economically illiterate and punish the poorest and most marginalized members of our society for a crisis caused by the banks".
The march in Glasgow left George Street at 1130 BST, with a rally due to take place at Glasgow Green. It is being led by former Remploy workers who lost their jobs when the government owned factories were closed.
Events in Belfast are concluding with a rally at Custom House Square. They have been organised by the Northern Ireland Committee of the Irish Congress of Trade Unions.
1238 Ian from Belfast
emails: No I will not be going. This march is about as pointless as an ashtray on a motorbike. We need to create private sector wealth just to keep all these "services", not try to recreate East German economy circa 1965.