Morcheeba's hits include The Sea and Trigger Hippy

Mayor of London Ken Livingstone has lined up the acts as part of his drive to boost tourism in the city and to showcase the revamped square in central London.

The last concert to be hosted in the square was in 2001 when REM performed for Nelson Mandela at a show to mark South Africa Freedom Day.

More than 10,000 people, who will be drawn from phone applicants, will be able to attend the show on 31 August.

Other acts due to join Gray, who found huge success with hits such as Babylon and The Other Side, will be announced over the coming days.

'Civic pride'

Ken Livingstone said: "David Gray and Morcheeba are hugely popular in the UK, but they're also major international artists, which makes them perfect to show off the wonderful new Trafalgar Square and the hundreds of other exciting things going on in London this summer and into the autumn."

David Gray said: "First and foremost the opportunity to play a free concert in central London doesn't present itself very often.

"I've always believed that in a city this size public gestures like this have an important part to play.

"London is a great city and in terms of civic pride it is lagging behind."

'Amazing place'

Skye Edwards, the singer with Morcheeba, said: "After we were asked to do this show, I happened to get off the bus just round the corner from Trafalgar Square and it suddenly dawned on me that it would be an amazing place to do a show."

Morcheeba, who have recently released a best-of album Parts Of The Process, have found fame for tracks such as The Sea and Trigger Hippy.

The concert is part of the Totally London initiative funded by the Mr Livingstone's London Development Agency.

People without tickets are being asked to stay away from the event.

Anyone who wants to apply for tickets should call 0870 511 2206 before midnight on Wednesday. Tickets will be drawn on Thursday.