Before work can commence, English Heritage must grant consent to allow changes to the grade II* listed building. Westminster City Council is said to be close to achieving this.

In July this year the Lord Chancellor, Lord Falconer, was forced to admit to the House of Lords that the costs of the project have already risen by more than ?3 million, and running the Law Lords at the Supreme Court is expected to cost ?substantially more? than today.

If the cost of moving the old courts out of Middlesex Guildhall are included, the price of the new court has risen from around ?50 million to ?53 million. The cost of running the law lords will rise by at least ?5 million a year when they move to the new site in 2009, from ?3-4 million to ?8-10 million. There is also no guarantee the costs of the move will not rise further.

English Heritage could still make conditions on the plans, and ?legal agreement? has yet to be reached between Westminster City Council and the Department for Constitutional Affairs to secure highways works, car-parking, furniture, public art and the restoration of the Middlesex Guildhall art collection.