Thanks for your question. I will try to help.
The child is not automatically entitled to as UK passport because they are not automatically a uk citizen in these circumstances.
This is because the father has UK citizenship “by descent” from his own father because he was born outside the UK. Citizenship can only descend one generation and because it has already descended once (from the grandfather to the father) it cannot now descend again to a child born outside the UK.
The only way that you might be able to get citizenship for the child at this moment in time, is by applying to register the child first as a UK citizen. This is different to automatically getting it.
If the father were able to prove that he spent three years in the UK without leaving for more than 270 days within those three years then you would likely be able to make an application under s3(2) of the British nationality act.
Please refer to the section titled “The law in relation to section 3(2)” at page 13 of the guidance:
You will see that it is possible that you might be able to apply in these circumstance under s3(2).
You will have to apply using form MN1 with the appropriate evidence and details of the form and guidance are here: https://www.gov.uk/government/publications/application-to-register-child-under-18-as-british-citizen-form-mn1
If you are successful in obtaining a certificate of registration as a UK citizen then you can then use this certificate to apply for the child’s passport.
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