I dont think you will be able to Wed in Lytham its not a designated office :(
found this on he web, hope it helps. Our marriage was in Church so the rules were different ( easier I think)-

If one or both of you are foreign nationals and subject to immigration control you have to give notice at a designated register office able to take notices for foreign nationals.

If I am a foreign national how do I get married or form a civil partnership?

If you or your partner are subject to immigration control, you need to give notice of a marriage or civil partnership.

You can do this at one of the 76 designated register offices in England and Wales. You must attend the register office together.

You will be asked for documentary evidence for some information, for example your nationality, so you will need to take your passport. You will also need evidence of the ending of any previous marriage or civil partnership.

If you want to come to the UK to marry or register a civil partnership, you will need to get the correct entry clearance. You will need this before you travel to the UK.

You are not subject to immigration control if you have the right of abode in the UK, or are one of the following:

a British citizen
an EEA national - see below for list of EEA countries
a member of visiting forces from NATO and Commonwealth countries
a diplomat that is not subject to immigration control

Religious marriage ceremonies

If you wish to be married in the Church of England – and generally you will be able to do so only if you or your partner lives in the parish – you should first speak to the vicar. If the vicar is able to marry you, he or she will arrange for the banns to be called on three Sundays before the day of your ceremony or for a common licence to be issued. The marriage will also be registered by the vicar and there is generally no need to involve the local superintendent registrar.

If you wish to marry by religious ceremony other than in the Church of England or Church in Wales, you should first arrange to see the minister or other person in charge of marriages at that establishment, which must normally be in the registration district where you or your partner lives. It will also be necessary for both of you to give formal notice of marriage to the superintendent registrar of the district(s) where you live. A registrar may also need to be booked.