The Queen and the Queen Mother enjoy the performance

Its new executive director, Michael Kaiser, welcomed the Queen and Duke of Edinburgh to the black tie event.

The performance, broadcast live on BBC Two and Radio 3, began with a rendition of God Save The Queen and continued with a memorable Royal Ballet performance with Sylvie Guillem, Viviana Durante, Irek Mukhamedov and Angel Corella.

Placido Domingo, Deborah Polaski, Stig Andersen and Robert Lloyd then led the Royal Opera Chorus and the orchestra under the baton of The Royal Opera's music director Bernard Haitink.

The programme also included the Overture to Weber's Oberon written for Covent Garden in 1826, the grand love duet of Siegmund and Sieglinde and the final scene of Fidelio.

The Queen's sister, Princess Margaret, who has recently been unwell, and the Queen Mother joined the royal party.

�214m has been spent on the revamp

Prime Minister Tony Blair and his wife Cherie, former premier Lady Thatcher and her husband Denis, and Ffion Hague were among the hundreds of VIPs.

The Blairs made a quick "meet the workers" trip when they arrived, talking to builders and technicians who had worked on the refurbishment project.

The three-hour exhibition received a standing ovation and the packed auditorium threw daffodils onto the stage to show their appreciation.

Afterwards the Queen stopped to congratulate ballerina Darcey Bussell.

Miss Bussell said: "She said she was amazed and had never seen so much ballet in one go. I replied `you have just seen a whole season of ballet in one show'."

The Queen also met the two youngest performers, Jane Hay, 10, and Rebecca Hartley, 9, both members of the Junior Associate of the Royal Ballet School.

Jane said: "I was shaking, really, really shaking but it was lovely."

Rebuilt venue

The venue's historic auditorium remains - but backstage and other areas have been extensively rebuilt.

One of Mr Kaiser's aims is to make the home of the Royal Opera and Royal Ballet more accessible to the general public.

The venue has frequently been accused of snobbery, elitism and mismanagement - leading to controversy when it was given a �78.5m lottery grant to help fund the redevelopment.

The new-look Floral Hall

That message was stressed in a message from the prime minister in the programme for Wednesday night's event, in which he underlined the government's wish to see the venue become a people's opera house.

Ticket prices have come down, and the venue also contains two new studio theatres, and has bars and restaurants which will be open during the day.

But the redevelopment has suffered from a host of problems. There have been years of bitter rows, as well as reports of spiralling costs and delays, and resignations and threatened walkouts by performers and electricians alike.

The hitches continued last week when six performances of Ligeti's opera Le Grand Macabre scheduled for this month were cancelled as it was found the venue's opening programme was too crowded, and some of the new equipment was not working properly.

The opening gala was televised live on BBC Two and broadcast on BBC Radio 3 - an extensive TV contract with the BBC is part of his new policy of openness and wider access.