You can't entrench Press Regulation law...

Many moons ago I learnt my constitutional law from an expert in the field who told me that you can't entrench an Act of Parliament, because the Act which requires a 2/3 majority in order to be amended can be repealed by a further Act -which only needs to 50% majority: No Parliament can bind its successor:

Parliament means, in the mouth of a lawyer (though the word has often a different sense in conversation) The King, the House of Lords, and the House of Commons: these three bodies acting together may be aptly described as the "King in Parliament", and constitute Parliament. The principle of Parliamentary sovereignty mean neither more nor less than this, namely that Parliament thus defined has, under the English constitution, the right to make or unmake any law whatever: and, further, that no person or body is recognised by the law of England as having a right to override or set aside the legislation of Parliament.

—A.V. Dicey Introduction to the Study of the Law of the Constitution (1885)

  That fundamental principle appears to have been lost in the recent all parties agreement to regulate the press by a Royal Charter which will require a 2/3 Parliamentary majority to be amended; or a 1/2 majority to repeal what will be section 92 Enterprise and Regulatory Reform Act.....Entrenched, it isn't....