Labour repeals part of Magna Carta
The link is to the debate about the Court Fees.
The old 1215 Magna Carta was changed on numerous occasions, but there are still some sections of the 1297 Magna Carta that are in force in the UK.
This can be seen here
on the statute law database.
One of the sections that remains in force is Section 29.NO Freeman shall be taken or imprisoned, or be disseised of his Freehold, or Liberties, or free Customs, or be outlawed, or exiled, or any other wise destroyed; nor will We not pass upon him, nor[condemn him,] but by lawful judgment of his Peers, or by the Law of the Land. We will sell to no man, we will not deny or defer to any man either Justice or Right
The government are proposing to charge fees for court access to include the cost of remitted fees for those people who cannot afford the fees. Whichever way you look at it this involves selling justice.
I don't think this can be done via an SI.