The move, announced at the start of international negotiations on sea dumping, were warmly welcomed by the environmental group Greenpeace which had been closely consulted by the environment minister, Michael Meacher.
The Government wants further curbs in the levels of nuclear waste discharges from Britain's two nuclear reprocessing plants, Sellafield in Cumbria and Dounreay at Caithness.
Redundant oil and gas rigs will have to be brought to shore to be dismantled, then disposed of or recycled, rather than dumped at sea. Only if it was unsafe or "impracticable" to do so would exceptions be made - circumstances which apply to a small number of massive concrete structures in Britain's northernmost offshore oil fields.
The previous Government had argued that the disposal of redundant deep- sea rigs should be dealt with on a case-by-case basis, although it had agreed that all rigs in shallow waters should be brought back to land.
Mr Meacher also announced that industrial pollutants would have to be curbed to the point where levels of any synthetic, man-made chemical in the oceans would be "close to zero". That meant a complete phase-out of any hazardous pollutants "within a generation" - taken to mean about 25 years.
Britain would never seek to dump any solid nuclear waste at sea, he added. The last government had also agreed to an international ban on dumping nuclear waste at sea lasting at least 25 years, but had wanted the option of reviewing this commitment after a scientific revaluation, scheduled for 2019.
There had been speculation that Britain might want to dump parts of its decommissioned nuclear submarines at sea in the long-term future. The Ministry of Defence yesterday confirmed the vessels - 11 have already been decommissioned - would be disposed of onshore.
Officials from the Department of the Environment have explained the new policy at a meeting in Brussels this week of the Oslo Paris Commission (OSPAR), a 14-nation body which regulates dumping and pollution in the north-east Atlantic.
Mr Meacher said on BBC Radio 4: "This is the most important change in UK marine policy for at least a couple of decades."
Greenpeace UK executive director Peter Melchett said: "The UK Government is, for the first time, giving British industry a clear, positive and accurate signal about the long-term need to stop polluting our seas."Reuse content