Mary Kate and Ashley Olsen have once again come under fire from PETA anti-fur protesters.

The twins - who have been nicknamed 'Hairy Kate' and 'Trashley Olsen' - turned up for a signing of their new book Influence at Barnes & Noble in New York to be greeted by a herd of campaigners wearing Trollsen Twins masks and carrying signs calling them 'fur hags.'

Angry protesters have targeted the diminutive duo because of their fur-packed wardrobes and clothing line.

"PETA has launched an online campaign, our Trollsen Twins Campaign, to raise awareness about how animals are treated on fur farms," says Ashley Byrne, PETA's campaign coordinator.

The ugly Trollsen Twins paper masks have proved so popular they have sold out online.

However Byrne says the masks are not intended to call Mary Kate and Ashley ugly - only their actions.

"It's that we think wearing fur is really an ugly choice inside and outside," she explains.

See the fur-lovers and the demonstration at Barnes & Noble below