There was a time, before the average bolg reader was born, when the SNP and Plaid Cymru were not allowed to make Party Political Broadcasts because they didn't represent the whole of the United Kingdom. Both parties overcame the ban by illegaly intercepting official BBC radio broadcasts in order to broadcast themselves. The Beeb, parliament and the public got so peeved by the interceptions that they eventualy allowed both parties the right to make official PPB's.
In England no party is alowed to make an European Party Political Broadcast, unles it stands candidates in at least nine UK constituencies. A situation that causes difficulties for Cornish Nationalists, who dont even have one national representative in the EU parliament, but have to share representation with the south west of England and Gibralta.
MK has made its first ever PPB. It wont be broadcast on the telly because of the racist anti-Cornish rules, but it can be seen on YouTube: