A business case for the redevelopment of the Queen's Building, part of London's Royal Courts of Justice, is due to be put to Lord Falconer, the lord chancellor, within weeks.
The Supreme Court group has put forward two option: either to refurbish the existing court buildings or to build new ones.

It is understood that the new-build option would mean that the courts would not be ready until 2008 at the earliest, particularly if government funding were to be sought.

Lord Justice Mance, the liaison judge with responsibility for the Royal Courts of Justice, has given his backing to the proposals.

Mance is adamant that the entire court complex, including the High Court, the Court of Appeal and the Crown Court, needs redevelopment. He described the central building as wasteful: "Just 12% of the space is taken up with courtrooms, compared with circulatory space, which takes up 70%."

The department of constitutional affairs, previously known as the Lord Chancellor's Office, is in favour of using the PFI to fund improvements to court facilities.

The five-acre site contains Victorian buildings, protected by English Heritage regulations, and 1960s buildings that are not subject to the same restrictions.