Organized by the National Rejoin March, thousands of people marched toward Parliament Square and demanded "we want our star back."
The protesters were carrying EU flags and wearing hats and t-shirts which also featured the EU flag. They were also carrying banners that called on the government to resign.
Mike Galsworthy, the head of the European Movement UK who also attended the march, said that Brexit is a betrayal of the working class and lower-middle-class workers in fishing, farming etc.
"We need all of the country to come together to call out Brexit for what it is and make sure that we rejoin the European Union and pick up our seats again at the table," he added.
In the referendum held in the UK in 2016, a majority voted in favor of the withdrawal of the country from the EU.
After the Brexit withdrawal agreement signed by the representatives of Britain and the EU on Jan. 24, 2020, the UK officially withdrew from the EU on Jan. 31, 2020.