TEHRAN (Press Shia Agency) – Over half a million demonstrators filled the streets of London calling for a referendum on the final Brexit deal, according to organizers.

People's Vote organizers called it the "biggest, loudest and most important" demonstration of its kind.

The People’s Vote campaign has had stewards stationed at regular intervals to estimate the size of the vast crowd that backed up Park Lane and spilled into Hyde Park before setting off towards Piccadilly and a mass rally in Parliament Square, the Guardian reported.

“Shortly after midday the sheer weight of number forced the closure of not only the southbound but also the northbound carriage way of Park Lane as the size of the crowd soared far above the massive march for a People’s Vote in June this year,” said a spokesperson.

“This makes it the second biggest demonstration this century behind the 1 million estimated to have protested against the Iraq War in 2003.”