Sandy Nairne is the director of the National Portrait Gallery, London

Yes: The circumstances of the sale being proposed by the Watts Gallery (two oil paintings, one by Albert Moore and one by Edward Burne-Jones) are very particular.

First, the two paintings were not given by George Frederic Watts as part of his founding legacy to create the gallery, but were added later. After many years of dormancy, the gallery has a collections development policy - the Watts Ionides painting was acquired last year - and these two other oils, although delightful, are not related directly to Watts, they do notfit within the gallery's original vision and fall outside its acquisitions priorities.

Secondly, the Watts Gallery is a small self-funding charity with no regular regional or national support. So this case is entirely different from local authorities deciding, wrongly, to consider selling off work when they still have other resources (raised by statute from council-tax payers) even if these are hard-stretched.

Thirdly, the gallery is not proposing to sell the works to fill a general revenue deficit, but to ring-fence the funds for much needed improvements to the care and conservation of the Watts collection. This is a crucial form of investment.

When applying any code of ethics to de-accessioning we need to be very careful to consider the overall public value. In this case I believe (given also that many works by these two artists are available within 40 miles) that a carefully thought-out sale, after consultation, can be justified.

Vanessa Trevelyan is the convener of the Museums Association's ethics committee

No: My concern about the proposed sale by the Watts Gallery is not that it wants to dispose of some of its paintings, but that it has selected paintings of high value solely to raise funds.

A museum by definition collects and preserves in order to make
material evidence available to the public. Selling collections, without any guarantee that they will remain within the public domain, diminishes access to our cultural heritage.

I think that a disposals programme should be part of a well thought through collections management strategy. There are many instances where objects will be more relevant, better cared for and more accessible in another museum, or public institution.

If, instead, a museum uses its collections as disposable assets this potentially destroys the trust the public has in museums in general.

There is a big difference between a private collection and a collection that is held by a charitable trust for the public benefit. A private collector has the freedom to acquire, trade up or sell. A charitable trust museum, set up to benefit the public, is rewarded for this laudable objective. It may benefit from tax exemptions, public donations and major grants from bodies such as the Heritage Lottery Fund or the Art Fund.

Selling collections results in a diminishing resource. How much of the collection do you need to sell before the museum becomes unsustainable due to lack of objects?