THE paper straws used by McDonald's - designed to be more eco-friendly than their plastic straws - cannot be recycled, it has been revealed.

Transcend Packaging, which is based at the Rassau Industrial Estate in Ebbw Vale, is one of two companies producing the straws for the fast food giant.

But according to an internal memo, the new paper straws are not recyclable and must be binned or burned, a national newspaper has reported.

McDonald's say this is a temporary measure as it works to find a waste processing solution.

Last year the company replaced plastic straws with paper ones across all of its UK and Ireland restaurants after a successful trial period.

Following criticism of the new straws, which some customers complained turned to mush in their drinks, a McDonald's spokesman said they were strengthened following feedback.

"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," the spokesman added.

"We are working with them to find a solution, and so the advice to put paper straws in general waste is therefore temporary.

"This waste from our restaurants does not go to landfill but is used to generate energy."

The move to paper straws came amid growing pressure on companies to reduce single-use plastic products and packaging.

It followed mounting concerns over plastic pollution in the oceans where items such as straws end up harming wildlife such as turtles and fish.

Global company Huhtamaki are the other company that produce the straws at its plant in Belfast.

The fast food giant also said that its plastic straws at the time were made from "100% recyclable material".

The spokesman for McDonald's said the company uses 1.8 million straws a day and that the move to paper was a "significant step in helping reduce single-plastic use".

"We are working hard to boost training and education in our restaurants to increase our recycling rates, and also encourage customers to recycle," he added.

"Over the past few years, the number of items we recycle has increased in line with our volume growth, in particular we have seen an increase in cups recycled - with 40 million recycled last year, however we recognise this is something we need to continue to focus on."