A ban on shark finning in UK waters is to be introduced by the government, ministers will announce this week. The practice, which involves slicing fins from sharks at sea and dumping their bodies overboard – often while still alive – has been heavily criticised by campaigners and blamed for pushing many shark species to the brink of extinction.

Shark finning was banned by the EU in 2003 but loopholes in the legislation have allowed fishing boats in UK waters to continue finning. It is estimated that hundreds of tonnes of shark fin have been landed since the European "ban" was introduced.

The government has decided to close this loophole, following the passing of an early day motion in the House of Commons. MPs demanded that "on no occasion should the UK government approve any derogation from the shark finning legislation in order to allow UK-registered vessels to remove shark fins at sea". The government has agreed to follow the example set by MPs, a decision that will be warmly received by wildlife groups, who have long campaigned for the UK to introduce a ban on finning.

Shark fins are used as an Asian delicacy – mainly as the key ingredient in shark fin soup – and sell for more than £200 per kilo. And it is this high price that has led to the spread of shark finning. Instead of taking the entire body of a shark back to port, fisherman hack off the animal's most lucrative parts, its fins, and then throw the rest of it away. The sharks can no longer swim and either starve to death or are eaten alive by other fish. Species targeted this way in UK waters include the shortfin mako, blue, smooth hammerheads and thresher sharks, as well as species such as Portuguese dogfish and gulper sharks.

Finning these species is officially banned by the EU. However, a derogation scheme allows member states to grant special permits that allow their fishing vessels to remove shark fins at sea provided the quantity of fins on board is kept below 5% of the weight of shark bodies. Many scientists say this figure is too high and allows fishermen to land two or even three fins for every shark carcass they land. Hundreds of tonnes of shark fin have been landed by the UK fleet under these permits since the EU shark finning regulation was adopted. But now UK fisheries ministers have decided to halt the issuing of these permits, a move that will ensure the UK fishing fleet complies with the original intent of the EU finning ban – that sharks are landed with their fins naturally attached. As Sonja Fordham, policy director of the Shark Alliance, recently told the BBC: "Requiring that sharks be landed with their fins attached is by far the most reliable means of enforcing a ban on shark finning."

The move should also ensure that fishermen catch far fewer sharks in UK waters and will be seen by campaigners as a significant step to help prevent many shark species being driven to extinction.

"Right now, the oceans are being emptied of sharks, and the scale of the problem is global," Dr Julia Baum, of the Scripps Institution of Oceanography in California, told the American Association for the Advancement of Science conference earlier this year. "If we continue, we are looking at a really high risk of extinction for some of these species within the next few decades."

With Britain agreeing to the ban on shark finning, attention will focus on Spain and Portugal, who are now considered the main shark finning nations in Europe and the primary obstacles to an effective EU finning ban. As part of this campaign, UK ministers are to write to Joe Borg, the European commissioner for fisheries and maritime affairs, to request an urgent review of shark finning regulation throughout the EU.