This week's front pages are rekindling interest in the ancient doctrine of parliamentary privilege. What is it, and is it being used in the right way?
The principle comes from the idea that MPs should be free to carry out their work without hindrance.
MPs often ask awkward questions about institutions, individuals and firms as they scrutinise legislation or raise issues on behalf of their constituents, and they’re often are involved in high-profile and sensitive debates.
- Read more: Judges granting Philip Green an injunction 'accelerated likelihood' of his identity being revealed
- Read more: Sir Philip Green named in Parliament as businessman in injunction scandal
In such an atmosphere, parliamentary privilege is a set of doctrines meant to ensure parliament can function without being improperly interfered with from outside.
This boils down to two factors: 'exclusive cognisance', which ensures only parliamentarians can control parliamentary affairs, and freedom of speech.
It’s the latter that’s currently the more controversial question.
How does parliamentary privilege allow MPs to break injuctions?
Watch: Lord Peter Hain names Sir Philip Green as the businessman at the centre of harassment allegations, using parliamentary privilege
Historically, the greatest threat to the supremacy of parliament came from an overly powerful monarchy.
The 1689 Bill of Rights provides “that the freedom of speech and debates or proceedings in Parliament ought not to be impeached or questioned in any court of place out of parliament."
In recent years, this provision and its successors have been interpreted as a way to get around certain court orders, such as injunctions and so-called superinjunctions.
An injunction can be ordered in court to stop someone - often a newspaper journalist - publishing information that can be argued is private or confidential.
A superinjunction is a type of injunction - but additionally the very existence of that kind of injunction cannot be reported at all without the journalist being in contempt of court.
Watch: Barrister Laurie-Ann Power tells Julia Hartley-Brewer why Sir Philip Green might have obtained an injunction. He has denied any wrongdoing
MPs have started to use parliamentary privilege to circumvent these rulings.
The Master of the Rolls (England's second most senior judge), then Lord Neuberger, wrote in 2009: “No super-injunction, or any other court order, could conceivably restrict or prohibit Parliamentary debate or proceedings.”
MPs cannot be sued for libel for what they say on the floor of the Commons or Lords.
Several other cases have touched on these issues.
Have MPs used parliamentary privilege to break injunctions before?
Ryan Giggs was named by an MP in 2011 after he obtained an injunction. Image: Getty
In 2009, Paul Farrelly MP tabled questions in Parliament that concerned an injunction obtained by an oil company, Trafigura.
The details spread like a rash on Twitter and online - despite attempts to restrict newspaper reports.
The injunction was overturned. But if anyone had wanted to know the details, a simple online search would have answered them before the court had ruled.
In 2011, Lib Dem MP John Hemming revealed an injunction obtained by Ryan Giggs regarding an alleged affair.
He also revealed an injunction obtained by RBS Chairman Fred Goodwin.
Is this a proper use of parliamentary privilege?
The entire debate can boiled down to the Roman question 'quis custodiet ipsos custodes' - who will guard the guards themselves?
To whom should the rich and powerful be accountable?
And should they be publicly accountable in affairs deemed by the courts to have the protection of privacy?
Likewise, who are MPs accountable to when they exercise parliamentary privilege to effectively overturn court rulings?
Should MPs (who have their own political aims) - and some of whom have or have had their own NDAs and confidentiality agreements - be allowed to exercise this power?
And is it a proper use of parliamentary privilege - which is arguably meant to protect parliament as a whole rather than the discrete interests of individual MPs?
The complex system of checks and balances in this country - the foundation of which goes back many centuries - is constantly challenged by developments in the new media age.
That will not change any time soon.