The Consumer Protection from Unfair Trading Regulations 2008. This prevents you from using intimidating or aggressive tactics to sell or falsely stating that a product will be available for a very limited time only, amongst 31 other unfair trading tactics that are banned. A guide to the Regulations can be found here.
The Consumer Credit Act. This provides consumers with a number of rights related to credit agreements, including a seven-day cooling-off period and the right to settle the credit agreement in full at any time. Read more on the Act here.