BROADCASTERS are "letting down voters" in Scotland across the UK by failing to invite the SNP to their live General Election debates, the First Minister has said.

Last week, ITV announced they would host a live head-to-head TV debate between Jeremy Corbyn and Boris Johnson but feature alternative party leaders in a follow-up interview-based programme.

Now, Sky News has announced it too will host a General Election debate - featuring the leaders of the 'three main UK-wide national parties'.

That meant Labour's Corbyn, Conservative Johnson and the LibDems' Jo Swinson. 

The LibDems are the fourth largest party in the House of Commons with 19 MPs. Meanwhile, the SNP are the third largest parliamentary party with 35 MPs. 

READ MORE: Corbyn, Johnson and Swinson invited to Sky News TV debate

Nicola Sturgeon reacted to the Sky News announcement negatively on social media. She wrote: "Simply outrageous and unacceptable to exclude @theSNP - the third largest party in UK. What are the other parties so scared of that they won’t agree to real debate? And why are broadcasters letting down voters, especially in Scotland?"

Meanwhile, Swinson - who had been critical of ITV's decision not to include her in their programme - responded to her invite by tweeting "I'm in". 

Earlier today, the East Dumbartonshire MP revealed her party was considering legal action if she is not invited to the ITV head-to-head debate ahead of the December 12 poll.

READ MORE: LibDems to launch legal action if Swinson not invited to ITV debate

An ITV spokesman said at the weekend: "ITV intends to offer viewers comprehensive and fairly-balanced General Election coverage.

"This involves a wide range of programming, including a live debate programme in which seven party leaders are invited to take part, as well as a live debate between the Labour and Conservative leaders."