The new link would use a disused railway tunnel

Initial investigations estimated the link from the Clyde waterfront would cost between �60m and �210m.

Strathclyde Partnership for Transport (SPT) has agreed to fund a further study at a cost of �250,000.

If the new link is approved it would be used to serve the 2014 Commonwealth Games.

SPT chairman, Councillor Alistair Watson, said: "This detailed study will bring the possibility of the subway link a step closer. It would make a major contribution to the redevelopment of the east end which is the driving force behind our plans.

"Of course the Commonwealth Games is a catalyst for this project but the main reason we are pursuing this proposal is the long-term benefit it could bring the east end of Glasgow in particular."

The potential route identified for the proposed extension starts at Bridgeton station, using a disused low level railway tunnel.

It would continue eastwards under London Road using the old railway tunnel, before surfacing at the eastern end of Celtic Park.