As a side note for first time buyers - avoid interest only mortgages these tend to be aimed at "professionals".
They look great but quickly F@ck you over.
See "endowment" mortgages.
Also be VERY wary of any mortgage over 5.5% . . . If your payments are around the £800 mark a 1/4% rise will equal £40 ish - at least.
Also note interest rates are likely to rise again soon.
Also, where possible, put a deposit down. Minimum 5%, but preferably 15%.
This way you'll get far more favourable interest rates AND shorter tie-ins.
Finally, ignore "incentives" . . . by this I'm talking cash backs . . . . these are pointless in the long term.
When I say ignore them, ignore them entirely when making your decision on a mortgage.