The private sector is not doing enough to make sure that more plastic bottles are collected and needs to take concrete action by December 1, government inspectors said on Monday.

“If not enough is done or achieved, the ILT (inspectorate) can take steps, including issuing fines,” a spokesman told broadcaster NOS.

The inspectorate first sounded the alarm at the beginning of September when it reported that only 68% of small plastic bottles are being recycled. The legal target is 90%.

Afvalfonds, the waste industry body charged with recycling, published its plan at the beginning of this month, listing several possible measures including changing consumer behaviour, introducing more collection points and expanding the deposit system to dairy and juice bottles.

Working this out in detail would take a further three months, the agency said at the time. The Netherlands introduced deposits of 15 cents on small bottles in July 2021. Cans followed this April.

The inspectors have now said they want to see a concrete plan in six weeks, and say that the industry is placing too much emphasis on consumer behaviour.

In addition, adding fruit juice and dairy bottles to the deposit scheme would enable industry to reach the 90% target, the inspectors said. They are currently exempt, but account for 20% of sales.

The introduction of deposits on cans and small plastic bottles has led to a surge in scavenging at railway stations and in cities.

Amsterdam in particular has been hit by a surge of complaints about rubbish bags being dumped on the street and torn open by people hunting for cans and bottles to take back to shops for cash.