see now Practice Direction 6).
Essentially, traditional court dress (gown, bands and wigs) need not be worn where all the parties to a case agree and also the Justices agree. The Revised Guidance states that the court will normally agree - thereby begging the question of when might they not agree. It appears that the initiative for this came from a UKSC User Group. The Guidance notes that court dress is not worn in family cases. Further, the Justices of the Supreme Court do not wear robes - (apart from during ceremonial occasions) - and they decided not to impose this obligation on advocates.
Prior to the creation of the Supreme Court, the House of Lords was at the apex of the UK's legal world. The Lords of Appeal in Ordinary ("Law Lords") did not wear legal dress - (again, apart from formal events such as the State Opening of Parliament) - and this carried over into
the Supreme Court when it was created. Strictly speaking, the House of Lords decided cases in the Appellate Committee and their Lordships delivered "speeches" as opposed to "judgments." The fiction was that they were addressing Parliament and this may explain the fact that the Law Lords did not wear court dress.
Maybe there was something of a case - (I would not put it more strongly than that) - for the Justices wearing at least a black gown once they had moved across Parliament Square to the new Supreme Court. However, it was not to be. Some elements of court dress should, I think, be abandoned permanently. Full-bottomed wigs and buckled shoes come to mind but do things really have to be taken to the other extreme so that even the wearing of a gown by advocates is to become a thing of the past?
Another factor is that court dress helps to reinforce the impartiality of the court. In my experience, Magistrates were frequently asked not to wear items such as ties indicating association with other organisations, flamboyant clothing or items of jewellery which attract attention. There may be problems in the future if such items were to become the norm.
No doubt, all of this will be claimed as progress in the interests of modernisation. For myself, I do not think it makes the court any more "accessible" as the guidance claims and it is a pity that we are now seeing the demise of this traditional part of the legal system. Greater accessibility of the court has been achieved by the move to the new building and also by televising of proceedings. I feel that something of the court's dignity will have gone with this announcement. Does it matter? I am not entirely sure but, on balance, I think it does.