Two mortgage offers

wildbreed100

I applied for two mortgages at around the same time and was offered the mortgage from lender 1 within 6 days (5yr fix 5.5%, £995 fee). I have just got word (after over a month) from the second lender that all is basically ok and they want to go ahead with the valuation. The second lender is the Post Office (5yr fix 4.45% £600 fee). The first lender has already written to my solicitor. I have not signed anything and I am in the early stages of the buying process.
Am I legally bound in anyway to the first lender ?. Can I ditch the first offer and accept the Post Office offer (assuming valuation is ok and the mortgage is offered).

I know I would lose my first lender valuation fee but that still works out cheaper. I applied first to the P.O but because of initial complications of being a new UK resident I did not think they were going ahead with the mortgage.

yelf

no you are not bound at all.

riqi

I wish I had those offers!

Could you say what's the LTV?

Thanks