The man, who is believed to be in his 40s, was taken to hospital with a life threatening head injury after being hit by a tram in Oldham in the early hours of this morning.
The collision took place close to the Sainsbury’s on Union Street, shortly before 12:20am.
He remains there in a critical condition and his family are being provided with support from specially trained officers.
PC Paul Hailwood of GMP’s Serious Collision Investigation Unit, said: “We are appealing for anyone with information about this incident to please come forward.
“We have carried a number of enquiries since this collision happened but we are keen to speak to anyone who may have witnessed it.”
Anyone with information should contact GMP’s Serious Collision Investigation Unit on 0161 856 4741 or the independent charity Crimestoppers, anonymously, on 0800 555 111.