Eric. In your other thread on the same problem here
http://www.theanswerbank.co.uk/Home_and_Garden /Question297042.html ........ you are now asking about best ways to try and protect yourself from losing this house (to someone else) whilst the CLU is applied for. I have taken the liberty of linking the 2 things together because your question has legal connotations and Jenna is likely to know more than me. I'm sure you know that under English Law there's no contract until Contract Exchange, however it may be possible for both sides to sign a separate but binding agreement (on both sides) that commits the vendor to sell at an agreed price, and you to buy at that price on condition that the CLU is forthcoming. Its a bit like an Option to Purchase agreement but binding on both sides. I guess you will unfortunately lose your costs of professional advisors incurred to date anyway (solicitor, mortgage application, survey fees), so it may be worth considering.