Hi
Please see the Moneysupermarket page http://www.moneysupermarket.com/mortgages/ for details.
You should read through the thread below regarding some problems people are experiencing buying new properties in the current market. Some people are having problems with Mortgage valuations which are less the selling price, which has caused some to pull out of buying, losing deposits, being charged by property company for losses.
http://www.moneysupermarket.com/community/forums/t/re-property-bought-offplan-for-09-completion-will-23656.aspx
With this information in mind, you should obtain advice from your solicitor about what you can do to protect yourself. The solicitor may be able to seek agreement to amend the contract terms with the property company, to offer you protection.
Huckster