The SNP has complained to Sky News and Ofcom about the channel’s decision to exclude Nicola Sturgeon from a general election TV debate, branding it “deeply undemocratic”.
Sky News announced plans on Monday for a live debate between Boris Johnson, Jeremy Corbyn and Jo Swinson on November 28.
It follows a threat of legal action by Swinson against ITV over its proposals for a head-to-head between Johnson and Corbyn which would exclude the Liberal Democrat leader.
The SNP has written to the head of Sky News as well as broadcast media regulator Ofcom demanding its inclusion in any debate as the third largest party at Westminster.
The party also said it could test the matter in the courts if the matter is not resolved quickly.
In the letter, SNP business convener Kirsten Oswald accused the news channel of failing to meet its “statutory obligations as a broadcaster”.
She said Ofcom election guidance bound broadcasters to include “an appropriately wide range of significant views” which are “given due weight in each programme”.
Special Ofcom election regulations to give balanced coverage to competing parties kick in at 12:01am on Wednesday.
Oswald said: “The disgraceful decision to exclude the SNP from the Sky News debate is deeply undemocratic and completely inexcusable.
“This is another example of the Westminster establishment closing in on itself and showing no regard for Scotland.
“The SNP is the third party in the UK Parliament, the governing party in Scotland, and as past election results and current polling shows, the party most likely to retain this position and hold the balance of power after the election – there is no excuse for shutting us out and silencing Scotland.
“This election will be one of the most important in Scotland’s history. The result could determine the UK’s relationship with the EU and the course of Scotland’s relationship with the UK – making it all the more crucial that the SNP are fully included in the debates.”
She said polls show the “overwhelming majority” of voters in Scotland and across the UK agree that the SNP should be included in the debates.
Oswald added: “It’s time Sky News and other broadcasters stop short-changing voters and do their job by recognising the multi-nation, multi-party nature of UK politics.”
Swinson has said she is taking legal advice and will “pursue legal avenues” against ITV if it does not change its two-party format to include her.
Asked during the Lib Dem campaign launch on Tuesday what her message to the Tory and Labour leaders would be regarding the debates, she said: “My message is I hope to see you there, or if not: what are you afraid of?”
The Liberal Democrat leader added: “I think it is ridiculous to suggest that the country is well served by a debate between two men who want to leave the European Union.”
Swinson also suggested sexism “has to at least be one of the possible explanations” as to why she has not been included in ITV’s debate plans.