Image copyright PA Media Image caption The sculptor called on BP to put half its profits towards renewable energy research

Sculptor Sir Antony Gormley has joined calls for London's National Portrait Gallery to end its sponsorship with BP.

BP has sponsored the gallery's annual Portrait Award for 30 years, but the oil company has faced growing criticism over its environmental stance.

Sir Antony said BP was "using culture to make us all feel this is a company that cares about the future of mankind, but it very clearly doesn't".

The gallery said BP's support for the award means public admission is free.

It added that government funding only made up a third of its income, so it has to work with corporate partners.

Sir Antony is one of almost 80 artists - including five winners of the Turner Prize - to write the letter demanding an end to BP's sponsorship.

In the letter to Nicholas Cullinan, director of the gallery, the artists state that BP's ongoing sponsorship "is lending credence to the company's misleading assurance that it's doing all it can, and so we, as artists, feel we must speak up".

"We believe that, today, the loss of BP as a source of funding is a cost worth bearing, until the company changes course and enables future generations to make art in a world that resembles our own," the letter continues.

Speaking to BBC Radio 4's Today programme, Sir Antony said: "Art is about giving a platform for sustainable futures... [it is] very clear that this is not a part of BPs remit".

Image copyright PA Media Image caption Sir Antony is best known for his Angel of the North sculpture in Gateshead

"We are in a crisis," he said, adding he would like to see the energy giant put half its profits towards renewable energy research,

"We are all immersed in a fossil fuel culture, we are all culpable. But there are a few organisations and governments that can do something about it."

'Extremely proud'

The letter calls on the gallery not to renew its contract with BP when it expires in 2022 and, in the immediate future, to remove the BP representative from the award's judging panel.

Peter Mather, head of BP in Europe, told the Today programme last week that the company was trying to help both the art world and the environment.

He said BP's 70,000 employees did not get up each day "with the intention of destroying the planet".

He added that BP was "extremely proud" of what it did in the arts, as well as what it contributed to the UK economy.

"We are focusing very much on reducing our own emissions. We are also improving - i.e. lowering - the carbon footprint of the produce that we supply."

It comes after artist and judge of this year's Portrait Award by BP Gary Hume said it was time to look elsewhere for sponsorship.

He said: "BP could continue to support the National Portrait Gallery without putting their name anywhere, it could be an anonymous gift.

"Without the institutions such as BP making a concerted effort... we haven't got a chance."