Iconic Brisbane restaurant Drift Cafe - formerly Oxley's on the River - has been almost completely submerged this morning.

The restaurant's pontoon has broken away and is floating down the Brisbane River covered with chairs.

Drift Cafe in Milton, formerly Oxley's on the River, is almost entirely submerged.

"[The restaurant] is very likely to sink sometime today. Salvage efforts were made yesterday, but in the interests of safety those efforts have now stopped," Premier Anna Bligh said this morning.