The SNP has mounted a last-ditch legal challenge over its exclusion from the final prime ministerial debate on the BBC.
Party leaders went to the Court of Session in Edinburgh to formally lodge papers in a bid to contest the BBC's decision not to include them in the live clash on Thursday night.
The SNP are seeking a judicial review of the decision ahead of the debate between Gordon Brown, David Cameron and Nick Clegg.
Nationalists have described the decision as a "democratic disgrace".
The legal action is taking place after the SNP raised £50,000 for a fighting fund to pay for the court battle.
Scottish Deputy First Minister and SNP deputy leader Nicola Sturgeon went to the court with Bruce Crawford, the party's business convener, to hand over the papers.
Speaking outside the court, Ms Sturgeon said: "This is a simple argument for fairness.
"The debate cannot and should not be allowed to go ahead while it excludes one of the main political parties in Scotland.
"This is not just about the SNP, this is about the right of voters in Scotland to have the choice they have on May 6 accurately represented to them."
