McDonald's have admitted that their 'eco-friendly' paper straws cannot be recycled, while previous plastic ones could be.

The fast food company swapped out its recyclable plastic straws last September for paper ones in a bid to go green.

However, an internal memo has revealed that the paper straws must be put in general waste bins and then burned.

"When McDonald's introduced paper straws it was getting pats on the back for being environmentally responsible,” an insider told The Sun.

They added: "But it seems like it was a stunt to appease green campaigners because the things go straight in the rubbish. It's ridiculously stupid."

The paper straws have come under fire from customers who said that they make it hard to drink milkshakes.

Before the change, McDonald’s had previously admitting to using 1.8million plastic straws in its UK restaurant each day.

They said its plastic straws were "100 per cent recyclable" but changed to paper because "more can be done".

Stuart Foster of plastic recycling charity RECOUP said: "Everyone is switched on environmental discussions but the big firms need time to understand what they're doing."

Former Climate change secretary Ed Davey said: "It really can't be that difficult to replace plastic straws. People will be left wondering where this was just greenwash or a monumental c**k-up."