Lord Sainsbury has given the British Museum a £25m donation to create an improved conservation department and expand the exhibition spaces in the gallery. It is understood to be the largest single private donation in the last 20 years. The Conservative peer was also responsible for the controversial Sainsbury wing at the National Gallery designed by Robert Venturi and opening in the early 1990’s. The original Richard Rogers design was rejected after the Prince of Wales compared it to a “monstrous carbuncle on the face of a much-loved and elegant friend. A spokeswoman for the museum described the donation as “incredibly generous”. She said the gift was a vital part of a project, which would “benefit future generations”.”This is an incredibly important project for the British Museum and has been planned for a long time,” the spokeswoman added. Donations from other private donors and a £22.5m government grant are also being used to fund the project, which will feature a science centre. The centre, which will cost more than £125m, will include a gallery to house temporary collections, which can compete with other UK and international institutions.The Sunday Times reported Lord Sainsbury’s gift as the biggest to the arts in Britain since philanthropist Sir Paul Getty pledged £50m to the National Gallery and £40m to the British Film Institute in 1985.In the same year, Lord Sainsbury and his brothers The Hon Simon Sainsbury and Sir Timothy Sainsbury financed the construction of the Sainsbury Wing at the National Gallery, which cost a total of about £50m and opened in 1991.Camden Council finally granted planning permission for the centre in October 2009 after modification of the proposed design.