The Save Trafford General campaign said the closure of its A&E department is "tearing the heart out of the hospital".
Matthew Finnegan, the campaign's chairman, said the future of the hospital - widely considered to be the birthplace of the NHS - is now "in real danger".
Mr Finnegan said: "These decisions can't just be made by clinicians - they have got to listen to what local people say. And people want an A&E, it's not an unreasonable request.
"Local people will be appalled and disgusted that they have not been listened to."
More top news
More than 400 people have died in a week of bombardment in rebel-held eastern Ghouta in Syria.
Coldest air yet to arrive
The band's hit singles include You To Me Are Everything, Can You Feel The Force?, and Can't Get By Without You.