The SNP failed in a last-ditch legal bid today to be included in the final prime ministerial debate on the BBC.
Party leaders went to the Court of Session in Edinburgh to contest the decision not to include them in the live clash tomorrow night.
But judge Lady Smith today rejected their bid to block the broadcast in Scotland of the debate between Gordon Brown, David Cameron and Nick Clegg if it does not feature the Nationalists.
In her ruling, Lady Smith said: “I am not satisfied that it is appropriate to grant the order sought.”
She added: “It seems to me that the order sought lacks the requisite precision and clarity and would leave the respondents in real and reasonable doubt as to what they could or could not do if they went ahead with the debate.”
Leaders’ debates have already been held on ITV and Sky and the final exchange is due to be hosted by the BBC in Birmingham tomorrow.
The legal challenge to the corporation came days after the BBC Trust rejected an appeal by the SNP and Plaid Cymru in Wales against their exclusion from the debate.
The SNP raised a £50,000 fighting fund in less than 48 hours to bring the court action, which got under way yesterday afternoon.
The party argued that its exclusion from the final prime ministerial debate was “inherently unfair” and said such a move ran contrary to the BBC’s requirement under its charter to show “due impartiality” in election coverage.
SNP deputy leader Nicola Sturgeon said outside court: “We are disappointed that the debate on Thursday night will go ahead without any substantial participation from the SNP.
“I believe that is wrong, it is unfair. We were simply asking for a fair hearing in that debate.
“I believe very strongly in the point of principle we were making.”
Sturgeon went on: “How can we expect people in Scotland to believe we will stand up for them when we don’t stand up for ourselves?
“We have stood up for a very important principle today and I am proud we have done that.
“We have taken a point of principle to the Court of Session today.
“I think we were right to do that. We have to take a stand when we believe debates are being conducted unfairly and I believe the debate that will take place tomorrow night is unfair to the SNP but, more profoundly, to viewers in Scotland, because it misrepresents the choice viewers in Scotland have on May 6.”
The SNP said it was not planning to appeal against the rejection of the interim interdict.
Ken MacQuarrie, who is the director of BBC Scotland, welcomed the ruling.
He said: “We are pleased to be able to bring the prime ministerial debate to the people of Scotland.
“In doing so we recognise the responsibility on us for due impartiality for us and also independence.
“We are pleased that the court recognised that we are discharging these responsibilities well with programming which is of substance and also impartial.”
Scottish Secretary Jim Murphy said: “These debates are for the candidates who want to be Prime Minister, everyone knows the SNP can’t win a British General Election.”