A campaigner for a navy base at Port Kembla sees the suggestion of a submarine fleet based there as just "phase one".

Senator Concetta Fierravanti-Wells has previously called for the navy to move out of Garden Island and into Port Kembla.

On Thursday, the Mercury reported Defence was considering placing the new submarines on the east coast, rather than basing them off Perth with the existing submarine fleet.

Port Kembla is believed to be a leading candidate.

In the Senate this week, the Senator discussed the future of Sydney's Garden Island naval base.

"It is also time to scale down Garden Island and build a naval base at Port Kembla, with our new submarines as phase one," Sen Fierravanti-Wells said.

"Since this idea was first raised in 2006, the changing security environment and the planned commissioning of a variety of new warships in the coming years have increased pressure on existing facilities, necessitating the navy's requirement for a new basing arrangement on the east coast."

By Glen Humphries

Published in the Illawarra Mercury