An article in the Daily Telegraph has claimed that the Lord Chancellor and the Lord President of the Council have “archaic rights” to vote in the House of Lords even though they aren’t peers (the article is behind a paywall, so I’m not linking to it). This comes from an anonymous “senior MP” who suggests that they could use this purported right to help the Government win close divisions in the House of Lords over the Northern Ireland protocol. While the basis for this notion isn’t specified, it’s likely inspired by section 8 of the House of Lords Precedence Act 1539. If that’s the case, the argument is specious.
The section in questions states:
And that if any person or persons which at any tyme hereafter shall happen to have anye of the saide offices of Lorde Chauncelor Lorde Treasorer, Lorde Precident of the Kings Counsell, Lorde Privey Seale or Chief Secretorie, shalbe under the degree of a Baron of the Parliament, by reason wherof they can have noe interest to give any assent or dissent in the saide House, that then in everie such case suche of them as shall happen to be under the saide degree of a Baron, shall sitt and be placed at the uppermost parte of the sakkes in the middes of the saide Parliament Chamber, eyther there to sytt uppon one fourme or uppon the uppermost sakk, the one of them above the other in order as is above rehersed.
While the Act does allow officeholders who aren’t peers to be present in the Upper House, it doesn’t follow that they’re somehow ex-officio members. While there were commoner Lord Chancellors/Lord Keepers, they could only speak in debate or vote if they were Lords of Parliament. Otherwise, they were limited to formal proceedings such as putting the question. The Lord President was usually a member of the House of Lords until the 20th century, and commoner Lord Presidents haven’t even sought to avail themselves of their seating privileges in the Upper House.
It’s worth remembering that, in the 16th century, there were a number of individuals who assisted the work of the Upper House without being members, including judges, Serjeants-at-Law, and Masters-in-Chancery. More than likely, this is what the drafters of the Act had in mind. They wanted to ensure the King’s advisors could be on the sidelines to assist the House even if they couldn’t speak in debate or vote. However, the practice of having non-members present in an advisory capacity has largely fallen by the wayside.
Ultimately, the Government can simply create new peers. Granted, that has its own downsides, but it’s better than relying on tortured interpretations of Tudor legislation.
 Erskine May, A Treatise Upon the Law, Privileges, Proceedings, and Usage of Parliament (London: Charles Knight & Co, 1844),152-153.
 See, G. R. Elton, ed., The Tudor Constitution: Documents and Commentary, 2nd edition (Cambridge: Cambridge University Press, 1982), 246.
 Or perhaps even control!
 Nowadays, Writs of Assistance go out to senior judges as well as the Law Officers of the Crown. While this theoretically enables them to advise the House, in practice, their attendance is limited to the State Opening of Parliament.