I am in similar position and exploring the followings option. Need to see if anyone has been successful using the "other cases" route.
UKBA Notes on Citizenship for children born outside UK
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http://www.ukba.homeoffice.gov.uk/briti ... thercases/
"Other cases where it is considered to be in the child's best interests to be granted British citizenship
British citizen
This page explains how a child born abroad to British or non-Brtish parents can be registered as a British citizen if it is shown to be in their best interests.
Applications for registration will be considered at our discretion under section 3(1) of the British Nationality Act 1981. When deciding whether to register a child as a British citizen we will consider:
the child's connection with the United Kingdom; and
where the child's future is likely to lie; and
the parents' views; and
the parents' nationality; and
whether the child is of good character; and
the length of time the child has lived in the United Kingdom; and
any compelling circumstances such as a job offer or other opportunity which requires British citizenship.
There are no formal requirements that the child needs to meet. We will consider the individual circumstances of each application. When you make the application you should make sure you provide us with all the information you think is relevant to the child's case."
