Cardinal Cormac Murphy-O'Connor launched a £3 million appeal on Thursday for Westminster Cathedral.

The appeal will fund a major programme of restoration work including urgent repairs to the cathedral's domes and the replacement of outdated electrical and heating systems.

"Westminster Cathedral", said Cardinal Murphy-O'Connor, "has been a symbol of the Catholic presence at the heart of our nation for over a hundred years.

"It is a Grade I listed building that is recognised as one of the finest examples of Victorian architecture and Byzantine art in the world.

"However, time has taken its toll and we must now take urgent action to ensure the future of this living house of prayer."

Cardinal Murphy-O'Connor explained that Westminster Cathedral does not charge an admission fee and does not receive any financial aid from the Government or from the Vatican, making it dependant on voluntary donations to pay for its running costs.

"Our parishioners do all that they can, but it is neither just nor realistic to expect them to shoulder the responsibility of maintaining the cathedral alone," he said. "I hope that the wider Catholic and national community will support our restoration appeal and help make sure that Westminster Cathedral can be passed on to the next generation and is properly equipped to deal with the demands of the 21st century."

Westminster Cathedral, which was consecrated in 1903, has always been well maintained. However, in 2007 a detailed structural survey revealed that three of its four domes and supporting brick arches have deteriorated to the extent that, unless they are immediately repaired, parts of the building might need to be closed. The work to renovate them will begin immediately after Easter 2008.

A second phase of work will modernise the cathedral's electrical and mechanical systems, most of which are worn out and inefficient, and also improve security and public access.

The restoration work, which is expected to take around two years to complete, will allow for the re-opening of the high level galleries at Westminster Cathedral which have been closed for over 30 years due to health and safety issues. The galleries provide a spectacular view of the nave of the cathedral, and when they re-open will provide up to 400 extra seats for a service or concert.

The cathedral will remain open throughout the restoration period, although there will be scaffolding in the building until Advent 2008 while restoration work is carried out on the domes.

It costs around £1.1 million a year to run Westminster Cathedral. Although donations to the cathedral have nearly doubled in recent years, it has not been possible to build up sufficient reserves to pay for the £3 million cost of the restoration work.

Mgr Mark Langham, Administrator of Westminster Cathedral, said: "Raising £3 million will be an immense challenge, but it is important to remember that it was only possible to build Westminster Cathedral because, 100 years ago, people within the Catholic community wanted a magnificent house of prayer and were prepared to pay for it.

"Our task today is to find people with a similar level of commitment."

He said that the fundraising programme would include a number of events organised by the Friends of Westminster Cathedral and applications to a number of grant giving bodies.

"Westminster Cathedral is the focal point for Catholics throughout England and Wales, and its mission is to manifest and promote the Catholic faith and its values within our society," continued Mr Langham. "We want it to inspire the worshipper and casual visitor with a sense of the presence of God. None of these goals can be achieved if we do not attend to repairing and modernising the fabric of the building."

Patrons of the restoration appeal include actress Patricia Routledge CBE, star of BBC1's 'Hetty Wainthropp Investigates' and of Alan Bennett's acclaimed monologues 'Talking Heads', and Sir Roy Strong, historian and former director of the Victoria and Albert Museum.