Campaigners have called for action after the maritime regulator ruled that foreign ships can continue to dump palm oil in British waters for three years.

In February, the International Maritime Organisation (IMO) approved regulation that will require tankers carrying palm oil and other food oils to pump the tank residue into purpose-built disposal facilities, instead of washing it out in open water.

But the new rules will not come into force until July 1, 2021, a timeframe the IMO says will give states and industry time to increase capacity at shore-based oil disposal facilities.

Britain already has the infrastructure required to deal with oil residue and experts say it should ban the dumping of food oils in British waters ahead of the 2021 deadline.