THE Save Galway Bay (SGB) group says it has collected thousands of signatures to a petition opposing the location of a sewage treatment plant on Mutton Island in the bay.
It wants to know why the scheme is being proceeded with at taxpayers' expense despite the environmental concerns of the European Commission.
The group has challenged the Minister for the Environment Mr Howlin, and the Minister for Arts and Culture, Mr Higgins, to debate the issue, claiming they have ignored the views of the EU, An Taisce, the Green Party and the Labour Party in Galway.
It wants the Ministers to attend a public meeting or meet environmental groups to answer questions raised by the proposal.
"With so many of Galway's citizens supporting us, we have to ask just how representative are the 12 city councillors who wish to have the plant placed in full view of tourists and locals alike in the centre of Galway's most famed visual amenity," an SGB spokesman, Mr John Cunningham, said.
He is a former election agent for Mr Higgins and left the Labour Party after Mr Howlin announced the exchequer would finance the project even without EU help.