The Bank of England has backed the use of palm oil in its new £20 note following a backlash from vegans and religious groups over the use of animal fat in the plastic £5 note.

The Bank said the world's most commonly used vegetable oil was the "only practical alternative" to tallow, following considerations about cost and availability.

Launching a public consultation on how future plastic banknotes should be made, the Bank estimated that using palm oil instead of tallow would add around £5m to production costs over the next 10 years of around £300m.

It said palm oil offered a "mature supply chain and is available at reasonable cost".

The Bank has started "extensive testing" of palm oil to ensure it meets "technical and operational requirements". The tests are expected to conclude this summer.