The government for ages has hidden behind the myth that the Erskine May rule stops discussion of the Royal Family in parliament. It doesn't.
The Speaker has just had to clarify that because of all the online discussions. Erskine May simply sets out that if the Royal Family (and some others such as judges) are to be criticised, it should be done properly in a formal motion. I've said it on here several times.
The government or the opposition could allow time for a motion to be discussed.
Speaker's comments are in this article
https://archive.is/pg1F6
Actual text of Erskine May
As indicated at para 20.10, unless the discussion is based upon a substantive motion, drawn in proper terms, reflections must not be cast in debate upon the conduct of the Sovereign, the heir to the throne, or other members of the royal family.1 The same principle applies to the Lord Chancellor,2 the Governor-General of an independent territory,3 and judges of the superior courts of the United Kingdom4 (including persons holding the position of a judge, such as circuit judges and their deputies, as well as recorders).'