A refugee who went on hunger strike after a row about his age with the Home Office, wants the Supreme Court to consider his case.
The Palestinian man settled in Bristol after fleeing Gaza and says he is five years younger than officials believe.
Last month judges said his life was in “danger” after he stopped eating.
At the time, Home Secretary Priti Patel said the case evokes the “greatest sympathy” but that she is under no obligation to change his birth date.
He restricted his intake of food and drink from March and has been in hospital since April.
Last month, court papers said he was accepting “some clinically assisted nutrition and hydration” in hospital.
The man, who cannot be named for legal reasons, applied to be a Nightingale hospital volunteer but was rejected as his claimed birth date did not match the one on his residence permit.
He took legal action in an effort to force the Home Office to change that date.
The man has said he is currently 26 years old but the Home Office has assessed his age as 31.
Supreme Court justices will first decide whether the man has an arguable case and no date has been fixed for a hearing.
Courts have previously heard how the man was born in Gaza, in the Occupied Palestinian territories, and that he had been “severely mistreated” by resistance movement Hamas for refusing to act as a suicide bomber.
He claimed asylum after arriving in the UK in 2007 and now has indefinite leave to remain.