There was applause and cheers as multiple speakers promised to resist the introduction of Covid-19 certification in Northern Ireland including many hospitality businesses who are already struggling to recover from previous restrictive measures.
Traffic was temporarily disrupted in the city centre, as many shoppers crowded into the Christmas markets in City Hall as the protest took place on the street outside.
Mr Swann has proposed that the Assembly is given the opportunity to debate the new regulations before enforcement comes into effect.
Meanwhile, police opened fire on anti-lockdown demonstrators in Rotterdam.
At least seven people were injured in running clashes, including three with bullet wounds according to local media.
Demonstrations took place right across Europe at the weekend as governments tighten restrictions.
There were protests in Belgium with police firing tear gas and water cannon at crowds, while an estimated 40,000 people took to the streets of Vienna to protest.
Thousands protested in Zagreb, Croatia over the mandatory use of Covid passports to enter public buildings while protesters in Milan and Rome clashed with police.
Other demonstrations occurred in Switzerland and even the French Caribbean territory of Guadeloupe.
