Despite the harsh tones, the demonstration has gone smoothly so far, according to the news agency AP.
British police are on hand to ensure that social distance is maintained and have announced that they may need to intervene if the rules are not complied with.
- I know that there is great frustration, but the rules have been created to protect the population from a deadly virus.
By many people gathering and ignoring social distancing, they risk their own health and the health of their loved ones, says police chief Ade Adelekan to AP.
As a result of the increased spread of infection, the government has announced that bars and restaurants will be forced to close as early as ten o'clock in the evening.
In addition, stricter restrictions on wearing mouth guards and a ban on public gatherings of more than 15 people will be introduced, however, demonstrations have been exempted.
Highest death toll in Europe
This is not the first time Londoners have protested against the measures.
Last week, equally large demonstrations took place in the square, during which a number of police officers were slightly injured when a small group of participants became violent.
Critics say the government has made a decision without parliamentary approval and that the measures are disproportionate to the magnitude of the coronavirus threat.
Britain has Europe's highest official death toll with over 42,000 confirmed deaths.
The number of new cases of infection in the country has also risen rapidly in recent weeks.
London is particularly affected and residents therefore risk being put under even tougher restrictions if the negative development continues.