Alasdair Taylor's Answer

By “pre-contractual terms” I assume you mean “pre-contractual statements”.  If such statements are terms of the contract, then they are not (merely) pre-contractual.

In any case, for a good summary of the position from Norton Rose Fulbright @ 2013, see:

http://www.nortonrosefulbright.com/knowledge/publications/109739/liability-for-conduct-in-pre-contractual-negotiations