“no enactment provides authority for the Commons to order by-elections to occur… one of the those truly unwritten constitutional things” blog.benl.co.uk/2019/11/disqua… @tc1415 on House of Commons disqualifications, by-elections, and writs of supersedeas #SitsVac
A by-election writ is ordered by warrant of the Speaker of the House of Commons – the only case in which the Great Seal is used without a royal or ministerial signature archive.org/details/in.ern… h/t Sir Wm Anson & Professor A. Berriedale Keith 
Though the Lord Chancellor is constitutionally keeper of the Great Seal and said to be responsible for its use, until 1851 a plethora of royal and ministerial forms, countersignatures and lesser seals were required before a typical instrument could be issued under the Great Seal ![Before 1851 a patent under the authority of a Secretary of State might pass through the following forms:<br />
<span class=]()
1. Warrant, signed by King and countersigned by Secretary of State addressed to Attorney-/Solicitor-General…
2. …Attorney-General’s Bill.
3. Bill signed by the King…
4. …transcript sealed with Signet…
5. …transcript…sealed with Privy Seal…
6. If Lord Chancellor saw no objection, he wrote his name under the grant…" src="/images/1px.png" data-src="https://pbs.twimg.com/media/EL2nDkTW4AQOc1W.png">
1. Warrant, signed by King and countersigned by Secretary of State addressed to Attorney-/Solicitor-General…2. …Attorney-General’s Bill.
3. Bill signed by the King…
4. …transcript sealed with Signet…
5. …transcript…sealed with Privy Seal…
6. If Lord Chancellor saw no objection, he wrote his name under the grant…" src="/images/1px.png" data-src="https://pbs.twimg.com/media/EL2nDkTW4AQOc1W.png">
By contrast, per Henry VIII, Royal Assent is “By The Queen Herself—Signed with Her Own Hand” with no ministerial warrant/signature (though the Clerk of the Crown whose surname appears on all sealed documents is Permanent Secretary to the Lord Chancellor)
A by-election writ embossed with the Great Seal. Dame Ursula Brennan was Clerk of the Crown in Chancery at the time. The returning officer signs the date of receipt (and in due course the name of the person elected) on the reverse or dorse, hence “endorse”
