Thousands of people marched through London today to protest against Britain leaving the European Union and to mark the bloc's 60th anniversary. Protesters took to the streets just four days before Prime Minister Theresa May launches the start of the formal divorce process from the 27 nation bloc. <br/><br/>Organisers said around 80,000 people joined the Unite for Europe march calling for Britain to stay in the European Union. A huge number of blue EU flags were waved by the protesters during this march. <br/><br/><br/>The anniversary of the EU's founding treaty was marked by a special summit in Rome, where at least 10,000 people also marched in support of the bloc. Around 4,000 people gathered in Berlin and rallies were also held across Poland in supporting the European bloc.