The Supreme Court ruled that the former Attorney General, Dominic Grieve, was not empowered to issue a certificate blocking the tribunal’s ruling that Prince Charles' letters should be released.

As a government minister, Mr Grieve, in seeking to overrule the tribunal’s verdict reached after hearing extensive argument, fell against two aspects of the rule of law: first, that the ruling of the courts is binding; second, that it is for the courts to review executive actions, not the other way round.

The Guardian's victory in this case has reinforced a fundamental constitutional principle: the President of the Supreme Court, Lord Neuberger, held that “a decision of a judicial body should be final and binding and should not be capable of being overturned by a member of the executive” – in this case, the Attorney General.

However, that was not a unanimous view. Lord Wilson, dissenting, criticised his fellow Justices of rewriting the Freedom of Information Act 2000, under which 10 years ago the Guardian had sought disclosure of the Prince’s letters to ministers. Lord Wilson argued that the majority view undermined parliamentary sovreignty.