Museums are to be urged to sell off some of their unused collections in a move that has provoked anger among leading arts figures.

The Museums Association, representing most of the country’s 1,500 institutions, will say today that disposals should become a routine part of the development of collections to make museums more “dynamic” and, in some cases, to raise funds for acquisitions.

Thirty years ago the association drew up a strict code of ethics outlawing sales of works of art. “De-accessioning”, as sales are known, is a dirty word in the museums’ world and the disposal of objects from public collections has long been condemned as cultural asset-stripping.

The association’s report, entitled The MA’s Disposal Toolkit, will send shockwaves through the corridors of some hallowed institutions. It outlines a change of heart in which the association will now argue that collections can become a burden unless they are cleared of unused objects. It will encourage curators to dispose of such items, by selling them or by redistributing them to other collections.

Meanwhile, the association has given its blessing to a sale of two important paintings from the Watts Gallery in Compton, Surrey. Edward Burne-Jones’s The Triumph of Love will be auctioned at Christie’s on June 5 for an estimated £600,000, and Albert Moore’s Jasmine for about £800,000. The association said that the works were from the gallery’s “noncore collection”.

Sir Hugh Leggatt, the former Museums and Galleries Commissioner, expressed outrage that anything could be sold by museums. He said: “Benefactors are not going to be excited to know that what they might give might be sold off one day.”

Opponents of the policy change point to the vagaries of fashion, claiming that Victorian works of art sold off in the 1950s, 1960s and 1970s for next to nothing were in some cases now worth millions of pounds.

But Sir Roy Strong, the former director of the Victoria and Albert Museum, welcomed the change. He said he had long believed that museums “can’t keep piling up the stuff forever – something has to go”.

Mark Taylor, director of the Museums Association, said that there were too many collections hidden from view. “Wonderful collections can become a burden unless they are cleared of unused objects. We’re professionals. We have to make those judgments.”

Sandy Nairne, vice-president of the association and director of the National Portrait Gallery, said: “Occasional responsible disposal of items will be increasingly important.” He predicted that sales would be occasional, although others gave warning that the new policy would be the beginning of a slippery slope.

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