Waitrose is on track to cut carrier bag use by 50% by the end of the year – but will have to increase this to 70% by next spring if it wants to avoid charging consumers, the government has warned.

Environment minister Joan Ruddock said that in the wake of Marks & Spencer’s drastic reduction in carrier bag usage following the introduction of 5p per bag charge, the government would introduce mandatory charging if the 70% target were not met. 

“When we met retailers recently, we told them we thought a reduction of 70% would be a ball-park figure,” she said at the Courtauld Commitment ministerial meeting this week. “That is the order of reduction. If the reduction can be achieved voluntarily, then excellent. If it can’t, we will impose charges. We know this is what the public wants.”

The news is not likely to go down well with retailers such as Waitrose, which have resisted moves to charge customers. 

Writing in his blog this week, managing director Mark Price said its 50% reduction would represent 155 million fewer bags

“I’m delighted that so many customers have seen the benefits of switching rather than us having to impose a tax,” he said. “And the recycling bins for our plastic bags are being heavily used.”

Ruddock’s announcement came as the grocery sector reported it had halted the growth of packaging in the UK despite a rise in grocery sales. 

The achievement had been delivered on the back of the Courtauld Commitment, a voluntary agreement between Wrap, Defra and 32 major retailers and suppliers.

The parties were now looking at ways of further reducing both packaging and food waste. 

Wrap called on retailers and suppliers to support its Love Food Hate Waste campaign to help it reduce household food waste by 150,000 tonnes a year by April 2010.