The National Association of Paper Merchants (NAPM) Boards Division added that while lead times for recycled materials were improving slightly, prices were holding at high levels.

Tim Bowler, NAPM director, said the shortage was due to mill closures and the fact that manufacturers outside of Europe were "currently not prepared to supply previous volume levels into the UK".

"New sources of supplies are being investigated but the process is proving extremely difficult to implement," he said.

In addition, the NAPM highlighted concerns that the market in the UK was still showing a substantial shortage in virgin fibre material.

Its members claim that other markets in Europe are being preferred to the UK and that the volume being supplied into the UK is "well short of actual requirements".

Bowler said there were also concerns from members that their customers were "accusing them of profiteering from the current situation", following the three mill price increases already issued in 2010.

"Members felt this was entirely unjust due to the market conditions," he added. "Pulp is a commodity and the increases over this year are visible to all via internet or financial sources."

The NAPM said that it was "near on impossible" to predict any price stability while the market conditions are so volatile.

The NAPM Boards Division consists of 10 members, paper merchants Antalis McNaughton, Careo, Cell, Deva Hawarden, Doric Anderton, Robert Horne Group, Paper Company, Penistone Paper & Board, Varsity Packaging and Warren Board Sales.

Between them they sell approaching 170,000 tonnes of board per annum.