The beaching of a ship near a World Heritage Site was carried out to stop a wider environmental catastrophe, the House of Commons has heard.
Containers are being removed at the rate of about 30 a day
Transport Minister Stephen Ladyman told MPs that oil would have washed up on beaches for many years if the MSC Napoli had sunk in the English Channel.
MPs and residents are concerned about the environmental impact on the area surrounding Branscombe beach in Devon.
Mr Ladyman said leaving it in Lyme Bay provided shelter for it to be salvaged.
The Napoli was deliberately grounded off the Devon coast on Saturday 20 January amid fears it would sink in deep water, after holes appeared on either side of the vessel two days previously.
It had been on its way to Portland port in Dorset under tow.
MPs, including Torbay's Adrian Sanders, have been asking the government why the vessel was being taken there instead of a closer port in Cornwall or Devon.
Mr Ladyman told the House of Commons on Thursday that Portland was chosen because French authorities could not identify a suitable place of refuge in France.
He added that the ports of Falmouth and Plymouth either did not have sufficient depth of water or the necessary facilities to handle containers.
After towing began, severe weather then started to cause structural problems on the vessel.
He told MPs: "With cracks on both side, it became clear would not reach Portland.
"The only viable option was to beach the ship in shallow water where there was a greater chance of successful salvage."
The first 70 containers salvaged from the 2,200 on the vessel arrived at Portland on Thursday morning.
Of the containers on board, 157 contained potentially hazardous materials.
Mr Ladyman said: "The contents of all the containers have now been identified - 103 were lost overboard; 57 of these have washed ashore and we are searching for the other 46."
He said the containers would be removed at the rate of 30 a day and that the removal of all them was expected to take five to eight months.
He said effort was being be made to bring this incident to a successful conclusion as soon as possible, but added: "At worst, the entire operation - pumping out the oil, lifting off the cargo and removing the ship itself - could take 12 months."
His comments came as the government official in charge of the salvage denied reports that the ship was in immediate danger of breaking up.
In the Commons, Mr Ladyman confirmed that as more were removed, the stress on the hull decreased, as did the risk of break-up.
He also said that the European Union's top maritime official, Fotis Karamitsos, praised the "efficiency with which the UK Secretary of State Representative dealt with the damaged ship".
Mr Karamitsos told the European Parliament that beaching the Napoli had "diminished the risk of catastrophe".
The complete operation may take up to a year
Maritime experts in the European Parliament are to debate the Napoli incident next Tuesday.
South West Regional MEP Graham Watson is planning a special hearing in Brussels to look at what happened and how a repeat of the incident can be prevented.
Local police have contingency arrangements in place to prevent a recurrence of the looting of washed-up containers seen on Branscombe beach last week.
Devon Fire and Rescue Service's fireboat, the Vigiles, is also in attendance off the beach in case the brigade is called on to assist in the salvage operation.
MSC NAPOLI SALVAGE OPERATION
The Napoli's containers will be unloaded from the stern first by crane barge Big Foot
A second crane on Big Foot will then transfer containers to shuttle barge Boa Barge 21
Shuttle barge will then transfer containers to Portland Harbour, where they will be offloaded
Lightering vessel Forth Fisher is positioned on the other side of the ship pumping off its remaining fuel oil
A decision will be made over whether to re-float the ship after all the oil and containers have been removed
Oil is being pumped off at a rate of approx. 20 tonnes per hour