Although the sector has been affected by a 50% across the board rise in timber material prices, packing case suppliers are particularly reliant on Russian birch plywood.

TIMCON, the Timber Packaging and Pallet Confederation, says prices for this grade have risen 50-70% in the past couple of months and supplies are now drying up.

A Timcon spokesman said: “The supply problem is not expected to improve in the short to medium term and there is a high risk of some confirmed contracts [with mills] still having to be renegotiated at higher prices.”

John Williams, managing director of Rowlinson Packaging Ltd, said: “Russian birch ply is in extremely short supply. In fact, we have been trying to get some this afternoon and we cannot find any available. It’s not just a matter of our customers shopping around. We are all in the same boat.”

UK furniture makers recently complained they were struggling to secure sufficient birch ply and UPM said this week it is negotiating to lay off 2,400 staff at five of its mills in Finland because of the lack of logs. Mills are now quoting October or November shipments with restricted volumes.

Mr Williams said: “China birch and poplar are available, but on a like-for-like basis they do not have the same performance so quite often you have to use a greater thickness, which can increase the cost 40-50%. Then you have to test the boxes, submit a sample, which all takes time,” he said.