https://www.gov.uk/government/publications/who-needs-an-entry-clearance-ecb04/ecb04-who-needs-an-entry-clearance#ecb43-deportees

ECB4.3 Deportees

An applicant who has previously been deported from the UK at any time must apply in writing for a revocation of the Deportation Order and wait for the outcome of the revocation request before they can travel to the UK (if a non-visa national) or before applying for an entry clearance (if a visa national). An application for entry clearance from a person with an extant Deportation Order will be refused automatically. Entry in breach of a Deportation Order is a criminal offence under section 24 (1) (a) of the 1971 Act. Any leave acquired prior to the Deportation Order is invalid.

This also applies to any European Economic Area (EEA) national - for more guidance on these see EUN1.3.

So it seems that you won't be stopped at immigration as an EU citizen but you would be committing a criminal offence by not having the deportation order revoked first.

Note: This answer is invalidated for the OP who may not have been deported at all but it still answers the question actually asked and may be the most helpful for others.

https://www.gov.uk/government/publications/who-needs-an-entry-clearance-ecb04/ecb04-who-needs-an-entry-clearance#ecb43-deportees

ECB4.3 Deportees

An applicant who has previously been deported from the UK at any time must apply in writing for a revocation of the Deportation Order and wait for the outcome of the revocation request before they can travel to the UK (if a non-visa national) or before applying for an entry clearance (if a visa national). An application for entry clearance from a person with an extant Deportation Order will be refused automatically. Entry in breach of a Deportation Order is a criminal offence under section 24 (1) (a) of the 1971 Act. Any leave acquired prior to the Deportation Order is invalid.

This also applies to any European Economic Area (EEA) national - for more guidance on these see EUN1.3.

So it seems that you won't be stopped at immigration as an EU citizen but you would be committing a criminal offence by not having the deportation order revoked first.

https://www.gov.uk/government/publications/who-needs-an-entry-clearance-ecb04/ecb04-who-needs-an-entry-clearance#ecb43-deportees

ECB4.3 Deportees

An applicant who has previously been deported from the UK at any time must apply in writing for a revocation of the Deportation Order and wait for the outcome of the revocation request before they can travel to the UK (if a non-visa national) or before applying for an entry clearance (if a visa national). An application for entry clearance from a person with an extant Deportation Order will be refused automatically. Entry in breach of a Deportation Order is a criminal offence under section 24 (1) (a) of the 1971 Act. Any leave acquired prior to the Deportation Order is invalid.

This also applies to any European Economic Area (EEA) national - for more guidance on these see EUN1.3.

So it seems that you won't be stopped at immigration as an EU citizen but you would be committing a criminal offence by not having the deportation order revoked first.

https://www.gov.uk/government/publications/who-needs-an-entry-clearance-ecb04/ecb04-who-needs-an-entry-clearance#ecb43-deportees

ECB4.3 Deportees

An applicant who has previously been deported from the UK at any time must apply in writing for a revocation of the Deportation Order and wait for the outcome of the revocation request before they can travel to the UK (if a non-visa national) or before applying for an entry clearance (if a visa national). An application for entry clearance from a person with an extant Deportation Order will be refused automatically. Entry in breach of a Deportation Order is a criminal offence under section 24 (1) (a) of the 1971 Act. Any leave acquired prior to the Deportation Order is invalid.

This also applies to any European Economic Area (EEA) national - for more guidance on these see EUN1.3.

So it seems that you won't be stopped at immigration as an EU citizen but you would be committing a criminal offence by not having the deportation order revoked first.