EU regulations now require all plastic caps remain attached to cartons and bottles to reduce plastic waste in nature, leading to the introduction of the cap, which cannot be removed from the milk packaging.

But customers reacted negatively to the new design, saying it makes it difficult to pour milk from the carton.

“We can already see that this is a moment of annoyance for people. We are therefore reacting,” Coop head of department Thomas Roland said in a statement.

Roland also pointed out that the old style cartons are not perfect, because they do not allow the cartons to be stored on their sides after opening.

As such, the company will keep the new lids on its other products while reverting to the previous carton on its five top sellers.

That decision was made because some products are more likely to be stored for longer, he said.

The change will not take effect into existing stocks are used up, which will be around March next year.

Plastic lids will be removed from 1-litre cartons of Øko-365 brand skimmed milk (skummetmælk), low-fat milk (minimælk) and organic Änglamark brand skimmed, low fat and whole milk (sødmælk).

Svend Schou Borch, CEO of Coop’s milk supplier Thise Mejeri, backed the decision.

“We don’t have screw caps on our own Thise milk products an applaud the use of less plastic because it suits our agenda of sustainability,” he said in the statement.