91Èȱ¬

A group 170 artists have added their signatures to a letter of protest about BP's sponsorship of London's Tate Britain gallery.

We answer some of the questions surrounding corporate support of the arts.

How are the arts funded and why is corporate sponsorship needed?

It is funded in three ways - from government income, box office receipts and sales of merchandise, and from corporate sponsorship and philanthropy. Each is dependent on the other.

We know government spending on the arts will be cut, perhaps by as much as 25%, as part of efforts to reduce the public debt.

If the economy takes another downward turn, ticket sales may suffer and people may also have less money to spend in an organisation's shop or cafe. So that leaves business investment, which currently accounts for about 3.6% of arts funding.

How important is arts sponsorship in the current economic climate?

It is crucial. Removing sponsorship would, according to Sir Christopher Frayling, the former Chariman of Arts Council England, "decimate the arts in some respects".

The government wants arts bodies to follow the US model and encourage more corporate giving.

Recent figures, however suggest government ambitions may be optimistic in the current economic climate. Business investment is down by six per cent - from £163.4m (2008/09) to £157.3m (2009/10).

Why are some artists concerned about the BP sponsorship of Tate Britain?

A total of 171 artists, including Hans Haacke and the playwright Caryl Churchill, have signed a letter to The Guardian newspaper complaining about BP's sponsorship of Tate Britain.

The gallery is holding a summer party to celebrate 20 years of support by the oil firm. The artists object to what they describe as "the environmentally destructive nature" of big oil companies in the wake of the oil spill in the Gulf of Mexico.

In the letter, they write that "the BP logo represents a stain on Tate's international reputation."

The National Portrait Gallery, The Royal Opera House and The British Museum are among the other cultural institutions BP sponsors.

Is protest against arts sponsorship a recent development?

No. Artists and activists have targeted the oil industry for many years. Shell was boycotted in the 1990s for its alleged involvement in the Nigerian government's decision to exceute the writer Ken Saro-Wiwa.

In the past arts organisations received support from tobacco companies and the arms industry. Protests indicate they are no longer regarded as suitable sponsors.

How do arts organisations defend their sponsorship?

They say sponsorship deals enable them to deliver successful and popular programmes to the widest possible audiences.

A joint statement from the Tate, The Royal Opera House, The British Museum and The National Portrait Gallery said: "The income generated through corporate partnerships is vital to the mixed economy of successful arts organisations and enables each of us to deliver a rich and vibrant cultural programme."

The Tate Gallery and The British Museum both have ethics committees which regularly review their sponsorhips deals.

The Royal Opera House has a Code of Fundraising Practice and the National Portrait Gallery does not have a written document, but the board of trustees discuss the ethics of potential sponsors on a case-by-case basis.