The new official was recommended by the former Master of the Rolls, Lord Donaldson, in his report on the botched salvage operation undertaken when the tanker ran aground off west Wales.

The official will intervene when there is a risk of significant pollution, but will only take charge of a salvage operation where necessary.

In the report published on Monday, Lord Donaldson said the lack of such a supreme commander had led to "control by committee" in the Sea Empress salvage operation.

Such an approach was "both ineffective and inappropriate", he said.

Environmental disaster

More than 72,000 tonnes of crude oil spilled from the Sea Empress over six-days in February 1996, after the tanker ran aground off St Anne's Head, Pembrokeshire.

Wildlife was devastated by the oil spill

It was one of the biggest oil spills in British maritime history with the widespread pollution leading to a coastal clean-up costing £60m. It is estimated that the whole incident cost almost twice that amount.

Earlier this year Milford Haven Port Authority was fined a record £4m - four times the previous maximum fine - after admitting guilt in allowing the disaster to happen.

Lord Donaldson's investigation also follows strong criticism of the salvage operation in a Marine Accident Investigation Branch report in 1997.

Warning on legal action

In his report, Lord Donaldson also questioned whether it was right that criminal prosecutions should be brought following incidents such as the Sea Empress disaster.

The threat of legal action could deter individuals from giving a full account at inquiries into marine accidents, he said.

However, Shipping Minister Glenda Jackson said that "prosecution and subsequent criminal sanctions are a necessary deterrent to causing deliberate or negligent environmental damage".

But she added that the government would review existing legislation to see what current offences and the legal defences were still relevant.

The minister also said that the Maritime and Coastguard Agency would seek to recruit an appropriate person to fill the new post.