Apparently, as soon as these regulations were passed, an amendment was made to allow national flags
On the 28 December 2001 the Department of Transport released this press release
"Motorists in Great Britain will be able to display national flags and symbols on their number-plates, Minister for Transport John Spellar announced today.
Mr Spellar said:
"The Government has decided to legislate to allow the voluntary display of national flags and symbols on vehicle number plates. It is what the people of England, Scotland and Wales have asked for and strengthens their feeling of national identity.
"We did have initial concerns about the ability of enforcement cameras to read the plates but these concerns have been overcome through enhanced camera technology. I am pleased to be able to make this announcement today."
The Road Vehicles (Display of Registration Marks) Regulations 2001 will be amended to allow national flags to be displayed on the left hand side of the number plate, in the area currently set aside for the voluntary display of the Euro symbol and GB national identifier.
Vehicle owners will be provided with the option of displaying either the Union Jack, Cross of St George, Scottish Saltire or Welsh Dragon accompanied, if they wish, by identifiers such as GB, ENG, SCO, CYM, UK etc.Those who choose to display a national flag or symbol on their number plates in preference to the European circle of stars and GB identifier will be required to continue to display a separate GB sticker when travelling outside the United Kingdom.