A new extension on two floors will contain a new education and conference centre and exhibits from archives. A major acquisitions programme has begun and the Holocaust exhibition project office is appealing for survivors to loan or donate material.
Director general Robert Crawford said the museum wants evidence of the Final Solution, of the communities it destroyed and testimony from those who survived.
The museum is applying for funds from the Millennium Commission for the building and wants matching sponsorship. Its remit is war in the 20th century, but the museum scarcely covers the Holocaust in its existing displays.
Mr Crawford said: "Education is at the heart of the museum's purpose." A fifth of visitors are organised school parties. Teaching is geared to all ages on themes ranging from the emancipation of women, the Russian Revolution and the rise of Hitler.
Field Marshal Lord Bramall, chairman of the board of trustees, said there had never been such a cold, calculated exercise to wipe out a people. He added: "Students of human nature will realise how these ghastly manifestations of hate, cruelty and indifference can come to the fore, which is why it is vital that the truth about this genocide should never be forgotten by future generations."
Holocaust Exhibition Project Office, Imperial War Museum, Lambeth Road, London SE1 6HZ, 0171 416 5285