Back in the 90s we weren't asked if we wanted to become EU "citizens". This newly-contrived identity was forced on us disingenuously and without our consent. And anyone wishing to renounce EU "citizenship" may not do so without also having to renounce their British citizenship at the same time.
There was no referendum about the Maastricht and Lisbon treaties in the 90s. The first referendum in the 70s was about the common market (belatedly, after we'd already been signed up).
Why should a common market need its own "citizenship", flag, parliament, supreme court, anthem, passport, motto, constitution, currency, foreign service, civil service, single legal identity, laws (replacing those of nation states, irrevocably), policies, presidents, free movement of persons (rather than just tariff-free goods), intelligence service, police service, diplomatic service, and plans approved last Thursday for its own tax ministry, finance minister and EU army?
Of course the EU threatens Britishness, and indeed the existence of all its member states as anything more than names of regions of a federal bloc. The EU's aim has always been "ever closer union", as it says in its founding Treaty (the Treaty of Rome). The EU has clearly been constructing all aspects of a superstate, stealthily over the decades, so there will be virtually nothing left to change in order to become a federal superstate overnight. And of course they hope no-one will really notice or care what has happened, and it will be too late.