While John Howard was PM, he is quoted as referring to the Magna Carta as a “historical document only”, but no government has the authority to repeal the Magna Carta since it was written before parliaments were ever formed and is in fact a covenant signed by King John in 1215.
The Magna Carta of 1215 is a covenant signed by King John on the Isle of Runnymede in 1215. Article 61 of the Magna Carta is included in this the original Magna Carta.
In 1297 the Model Parliament confirmed Magna Carta in statute law. Much of this statute has since been repealed. Yet while Parliament can repeal or amend any Act of Parliament (statute), Parliament was not a party to the original Common Law contract of 1215, and cannot, therefore, amend or repeal it lawfully, and thus its original provisions remain intact, including article 61.
We are an English Common Law Commonwealth country (Constitutional Monarchy), and there has been no successful referendum to change that status, contrary to some politicians beliefs.