EU citizens (with some narrow exceptions for indigent Romanians and Bulgarians) cannot be "deported" from the United Kingdom.

They can be "removed" from the UK and subsequently "excluded from exercising rights of movement", but only in cases of serious risk to public safety and security. If you have indeed been subject to one of these removal orders, you will not be able to transit via a UK port as your name is on an active E-Borders watchlist.

If your "deportation" was a result of being an indigent Romanian or Bulgarian citizen in the UK, you will be subsequently permitted to transit and even enter the UK provided you do not intend to do so for more than 90 days with no means of support.

If in doubt of your status, please check your UKBA/UKIS paperwork concerning your previous removal from the UK and contact your local British Embassy for further clarification.