Hundreds marched on Parliament Square from Oxford Street and Regents Street earlier despite fears that a mutant strain of coronavirus is spreading rapidly around the city.
Police had warned people not to attend large gatherings so close to Christmas and extra officers were deployed to try to ensure social distancing rules were followed.
But there were ugly scenes as officers attempted to control the crowds and several protestors were led away into police vans.
There were several clashes between officers and unmasked demonstrators, who chanted ‘we demand freedom’.
Andreas Michli, the owner of a gym in Wood Green that refused to shut its door during the second national lockdown, was one of multiple people who has been arrested.
‘I’m going to keep doing this until we’re free,’ he said as he was led to a police van.
It came as Boris Johnson announced that several areas of eastern and south-east England would be placed under tier four restrictions – the toughest in the UK.
Protestors, many of whom weren’t wearing masks, marched through the centre of London carrying placards that said things like ‘Why vaccinate for something 99% of people beat’ and ‘It’s not about a virus, it’s about control.’
The Metropolitan Police account later tweeted: ‘We arrested 29 people today following demonstrations across the city.
‘Unacceptably five of our officers were injured – thankfully their injuries are not serious.’
Before the demonstration began, Scotland Yard issued an open letter urging people not to attend.
The force said extra officers will be on London’s streets to encourage compliance with strict regulations and to ‘swiftly clamp down on those wilfully and dangerously ignoring them’.
Other protests took place in UK cities across the country but the one in London was the largest.
The open letter asked people not to attend any large gathering and warned they may be at risk of committing a criminal offence if they do.
Coronavirus laws outlaw gatherings of more than six outdoors, although there is a list of exemptions which includes protests where all relevant safety precautions are in place.
The Police Federation, which represents rank and file officers in England and Wales, earlier this week wrote to Home Secretary Priti Patel highlighting the health risks to those policing protests.
National chairman John Apter and Met Police Federation chairman Ken Marsh described the Christmas footfall coupled with a mass demonstration as a potentially ‘deadly and unmanageable mix’.
Deputy Assistant Commissioner Laurence Taylor said: ‘Where we become aware of planned events that will breach regulations, we will try to engage with organisers or venues to make them fully aware of the restrictions that are in place to keep people safe.
‘However, if people do not listen to our advice and fail to comply with the rules, we will be forced to take enforcement action.
‘With infection rates rising rapidly across the capital, we all need to play our part in preventing the spread of the virus.
‘This is the final weekend before Christmas, so now is not the time for complacency. I know Londoners know what they should and should not be doing and I would urge everyone to act sensibly and do their part to keep our city safe.
‘Sticking to the guidelines put in place to keep us all safe and well is now more important than ever.
‘This weekend we will ensure we deal with the activity of a few so as not to expose our communities at even greater risk during this pandemic.’
Some 11 people were arrested after a demonstration by about 200 protesters in London’s Parliament Square on Monday for alleged offences including breach of Covid-19 regulations, Public Order Act offences and assaulting an emergency worker.
During the second national lockdown at the end of November more than 150 people were arrested as activists marched from Hyde Park to Oxford Circus and Regent Street, clashing with police.
Push will get a person almost anywhere- except through a door marked “pull.”