The protection of fundamental rights as a general principle of EU law was established long before the UK joined the European Communities.
The ECHR was recognised as a source of such rights both in the case law of the ECJ and in the Treaty on European Union agreed at Maastricht in 1991.
The Charter of Fundamental Rights incorporated into the TFEU is a codification of such rights.
The Charter does not expand the scope of EU law.
The protocol to the Treaty of Lisbon in respect of the UK and Poland is not an ‘opt-out’ from the Charter – it simply reinforces the fact that the Charter (unlike the ECHR) is not an instrument of general application against the Member States but only applies within the scope of EU law.