Ask an Immigration Solicitor. Get an Answer ASAP.
I can help you for your concerns.
Your partner is illegal?
Where is his previous passport?
how long you have been living together?
it is not a good idea to make a new passport for marriage because your partner's passport is with the Home Office.
if he make a new passport and will try to get marry in UK in registry office then registry office may inform to home office. Home Office may arrest him for this action.
if you both have a baby with British Passport then he can apply as parent of a British child.
he can apply for family life in UK under human rights.
i hope it will help you
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