A levy on carrier bags came into effect on Monday this week in Northern Ireland, the second part of the UK to impose the charge. Wales was the first, in 2011.

The move has proved unpopular with Northern Ireland retailers, who must now collect 5p for every bag used.

Diana Gass, MD of Creative Gardens, who have garden centres at Donaghadee in County Down and Bushmills in Country Antrim, said: “We were initially worried about it. We felt it is very bad customer service to charge for bags, especially for more expensive items of clothing or giftware.

“By and large customers seem to have taken it in their stride and understand the issue. It has been quite well publicised so many bring their own bags with them.”

She said consumer reluctance to pay the levy had dramatically reduced their use of bags. “We are selling our own reusable bags, as we always have, but not many. We of course can, and do, supply boot liners and plant trays and boxes free of charge.

“Customers are inclined to take the shopping basket to the car so we may find that any saving we make on bags will be taken up by replacing baskets!”

The Irish Republic introduced a bag tax in 2002 and has raised £180m to date for environmental protection projects. The Northern Ireland Minister says the new levy will be spent in a similar way. He is also considering a further 10p levy on reusable bags.

How long will it be, we wonder, before England and Scotland follow suit?