Shutting up shop

My clients gave up trying to make their business profitable after falling out with a major customer. They effectively closed all operations dismissed all five employees and paid redundancy etc. After a long dispute they recovered through the courts over £500 000 consultancy fees from the aforementioned customer. Until recently they hoped to sell the former business premises but this has fallen through. The sale of the premises will probably now not take place until 2009 or later.

Assuming that the partners make a capital gain on the disposal of the premises at what point will they cease to be able to claim entrepreneurs' relief? I need to give them a deadline past which their capital gains tax rate jumps by approximately 80% to 18%.

I can see that TCGA 1992 s 169I(4) lays down a permitted period of three years. From what...