Open Britain Shrewsbury filled The Square to provide members and residents the opportunity to raise their concerns and push for a "people's vote" on Brexit.
Chants of "we want democracy" filled the street as people rallied against the decision to prorogue parliament, calling for a second referendum to take place.
Mark Fermor, spokesman for Open Britain Shrewsbury, said: "What we can see now in the latest political development is an absolute meltdown in our democracy.
"It's fundamentally because we haven't been scrupulously following democratic procedures and people have been claiming falsely that the referendum in 2016 was made as a clear choice that we as the public could understand - which could then be easily implemented.
"We can see now people in parliament are taking ever more extreme directions away from a democratic process."
Earlier this year, hundreds of members of the group joined campaigners in London to rally for a second referendum on the Brexit decision.
And in October last year, Open Britain Shrewsbury organised transport for more than 200 people to travel in four coaches to join more than 700,000 supporters on the previous people’s vote march.
Mr Fermor added: "Open Britain Shrewsbury are campaigning for that referendum and we're really here to voice our concerns and defend our democracy.
"We need to stand up for the rule of law otherwise there won't be a place for the UK in having western liberal values that should be assumed - but now we are having to shout out to save those values."