The government has identified 32 Marine Environmental High Risk Areas (MEHRAs), in which the perceived impacts on marine and bird life of any shipping disaster involving oil or other toxic substances would be disastrous.

The areas will be marked on Admiralty charts and ship captains asked to exercise particular caution near them, giving them a wide berth if possible.

The MEHRAs cover 9% of Britain's coastline, but complaints are already arising over omitted areas, such as the Scilly Isles and western Scotland's Minch.

The idea for MEHRAs emerged from the late Lord Donaldson's report into the 1993 Braer tanker disaster.