They may be “eco-friendly,” but McDonald’s new paper straws cannot be recycled — and must be tossed along with general waste, according to a report.

McDonald’s last year eliminated plastic straws in all of its UK outlets as part of a green drive, despite the fact that they were “100 percent recyclable.”

But according to an internal Mickey D’s memo cited by the UK’s Sun newspaper, the new paper straws “are not yet recyclable and should be disposed of in general waste until further notice.”

“As a result of customer feedback, we have strengthened our paper straws, so while the materials are recyclable, their current thickness makes it difficult for them to be processed by our waste solution providers, who also help us recycle our paper cups,” a McDonald’s rep told the BBC in a statement.

The spokesman added: “This waste from our restaurants does not go to landfill, but is used to generate energy.”

The company switched from plastic to paper straws in its restaurants in the UK and the Republic of Ireland last autumn. They are made by Transcend Packaging, based in Ebbw Vale in South Wales.

McDonald’s uses some 1.8 million straws each day in the UK alone.

But many customers were not lovin’ the new straws, saying they dissolve even before a drink could be finished. A petition to bring back plastic straws has so far been signed by more than 50,000 people.

An insider told The Sun: “When McDonald’s introduced paper straws it was getting pats on the back for being environmentally responsible.

“But it seems like it was a stunt to appease green campaigners because the things go straight in the rubbish. It’s ridiculously stupid.”

If not recycled, some single-use plastic products can take hundreds of years to decompose. Most straws are made from plastics such as polypropylene and polystyrene.

Julian Kirby, plastics campaigner at Friends of the Earth, said: “For too long the debate has been stuck on recycling and how to deal with waste once it is created. We should be thinking about how to avoid waste creation.

“Lips have been a waste-free alternative to straws for millions of years,” he added.