A passport is issued by the state you are a citizen not by the EU even if it says European Passport which is followed by the state you are a citizen.
Here are some info. Best to contact the nearest British Embassy.
You can apply for a British passport if you belong to one of the groups listed below.
* British citizens
* British dependent territories citizens (BDTCs)
* British overseas citizens (BOCs)
* British subjects
* British nationals (overseas)
* British protected persons
Anyone who is a British citizen is entitled to apply for a British passport.
On January 1 1983, anyone who was a citizen of the United Kingdom and Colonies on December 31 1982, and had the right of abode* in the UK, became a British citizen.
* NB There may be individuals who have the right to live in the UK but will not have the right of abode in the UK as defined by the Immigration Act 1971, and will not therefore become British citizens " see below
That includes people who
* were born in the United Kingdom;
* were born in a British colony and had the right of abode in the UK (Those born in a British colony and did not have the right of abode in the UK will not become British citizens)
* have been naturalised in the United Kingdom;
* had registered as a citizen of the United Kingdom and Colonies; or
* could prove legitimate descent from a father* who one of the above conditions applied to. Before the introduction of the British Nationality Act 1981, a person could not claim nationality from his or her mother.