The exclusion of the SNP from the final prime ministerial TV debate is "inherently unfair", a court was told today.
The Court of Session in Edinburgh heard the criteria used by the BBC to justify the move was "unreasonable and discriminatory".
It was further argued that the Nationalists' exclusion from Thursday's clash runs contrary to the broadcaster's own election guidance and that the balancing coverage the SNP has been given is "inadequate".
The statements were made as legal action over the scheduled debate between the UK party leaders got under way this afternoon.
The Nationalists are furious that they are not set to be part of this week's live debate between Gordon Brown, David Cameron and Nick Clegg.
Their action is seeking to ensure that the debate is broadcast in Scotland with the nation's political make-up "fairly" reflected by the national broadcaster.
The court papers state that the party is seeking an interim interdict against the BBC broadcasting the leaders' debate in Scotland if it does not feature the SNP.
The party was able to proceed with its legal action after it raised £50,000 in two days to fund the last-ditch battle. Legal papers were lodged at the court this morning.
Mungo Bovey QC, for the SNP, began the hearing by outlining the arguments on behalf of the party.
Referring to the official papers, he said: "The first chapter is that the exclusion of the petitioners' representative from the debate, which is the subject of this application, is inherently unfair."
He said the SNP's preferred representative on the programme would be leader Alex Salmond, although an election candidate could also appear.
He went on: "The criteria used to justify the exclusion of the petitioners from the debate are unreasonable and discriminatory.
"The exclusion is contrary to the BBC's own election guidance."
Mr Bovey told judge Lady Smith that the airtime, or "balancing coverage", which has been given to the party is also "inadequate".Reuse content