Red-tinted spotlights will shine inside the huge £758m structure illuminating the roof all day and night on 12 March.

Air travellers will have a superb view of the massive nose as they fly over the Dome site in Greenwich, south-east London.

Comic Relief organisers and the Dome's management company, the New Millennium Experience, agreed a plan to light the building in aid of the charity day.

"The Dome will be lit from the inside so that the roof glows red like a giant nose," said an NMEC spokesman. The stunt is believed to be costing about £100,000.

The red noses are a symbol of the annual charity day - and this year's noses make a squeak when squeezed. They are on sale for £1 in stores across the UK, with 70p going to Comic Relief.

Comic Relief day will feature a six-hour telethon on BBC One which aims to raise record funds for charities in the UK and Africa.