Following pressure from our campaign, in 2007 Manchester City Council replaced the old mealy-mouthed blue plaque with a new red one, using wording that we provided.

Mouse-over the image of the blue plaque below to see the new version:

The plaque is sited on the wall of the Radisson Hotel (the Free Trade Hall as was), and is the only memorial in the vicinity of St Peter's Square.
If you want to take a look it's on the corner of Peter Street and Southmill Street, here's a map.

The new plaque is red as this is the colour now used to "..celebrate or commemorate events of importance to the social history of the City..".
Blue is for individuals or the building they lived in, and black for buildings of special interest. And not everyone knows that.

However this Blue Plaque in Middleton marks where Bamford's contingent gathered before heading to St Peter's Field:

"The word "democracy" has been tarnished by the politicians who benefit from its Parliamentary form.
But do not forget that people fought and died for democracy, for the right of universal suffrage.
The Peterloo Massacre was one such event but the calls for freedom, justice and democracy were meet with murder and suppression.
The shameful object that seeks to serve as a commemorative plaque to this event hides the struggle of working people, it hides the urgency of their demands and the brutality of the state.
To fail to refer to the massacre, to fail to refer to the deaths and instead skip over these events is an act of historical vandalism akin to Stalin airbrushing dissidents out of photographs."

Mark Thomas, comedian