Anti-cuts campaigners and health workers have joined forces in central London in protest against the planned shakeup of the NHS.
More than 2,000 people staged a sit-down protest on Westminster Bridge from 1pm on Sunday to highlight the health and social care bill, which is due to go before the House of Lords this week.
The bridge, normally one of London's busiest, links St Thomas's hospital on the southern bank with the Houses of Parliament.
As Big Ben struck 1pm protesters unfurled banners and sat down, blocking the bridge in both directions as hundreds of police looked on.
UK Uncut, the anti-cuts group which organized the Block the Bridge, Block the Bill demonstration, said: "Today has brought together doctors, nurses, parents, students, unions, pensioners and children together in an unprecedented act of mass civil disobedience.
"We are occupying the bridge because the bill would be bad for the NHS, bad for patients and bad for society."
The protest drew support from people across the UK. Janet Bennett, a pensioner who had traveled down from Liverpool said: "The NHS is so important to people in this country and we need to stand up and protect it from this creeping privatization, and this is why I am here today."
Susan Secher, 53, a human resources manager from London said: "Our greatest fear is that the NHS will end up as an insurance-based two- or three-tier system … the bill is being pushed through and this is our last chance to stop it and people are becoming desperate."
Just after 2pm, protesters dressed up as medics unfurled a banner over the side of the bridge reading "Save our NHS".
Sam, a therapy radiographer from London, said: "The NHS is the greatest invention in this country's history, providing universal healthcare for all. If it is sold to private companies this will no longer be the case."
The second reading of the bill on Tuesday and Wednesday has more than 80 peers tabled to speak.