15 celebrity images from Greenpeace's Save the Arctic campaign

Having campaigned on issues from fracking to nuclear disarmament and climate change, Westwood has become as famous for her activist work as her fashion designs in recent years.

The two often meet, with Westwood creating a childrenswear line bearing the slogan 'I am not a terrorist', presenting her AW11 collection against the backdrop of a Nairobi slum and dedicating her SS14 collection to jailed whistleblower Chelsea Manning.

Most recently the designer shaved off her hair to draw attention to the impacts of climate change and appeared in a PETA video in support of World Water Day.

She is a vocal supporter of the Green Party and reportedly donated £300,000 to its 2015 general election campaign.

Members of the public who are persuaded to join the Save the Arctic campaign will have the opportunity to purchase the T-shirt - which comes in baby, child and adult sizes - from Westwood's website with all profits going to straight to Greenpeace.