The Lib Dems and SNP have lost their legal challenge to be included in an ITV head-to-head debate ahead of the general election on 12 December.
The channel is due to air a face-off between Tory leader Boris Johnson and Labour’s Jeremy Corbyn on Tuesday.
But the Lib Dems said they wanted their pro-Remain stance to be represented, while the SNP also wanted the issue of Scottish independence to be raised.
But judges ruled there was “no arguable breach of the Broadcasting Code”.
In the High Court in London, Lord Justice Davis and Mr Justice Warby said the case was not suitable for judicial review as ITV was not carrying out a “public function” in law by holding the debate.
However, the parties had the right to complain to Ofcom about the programme after it had been broadcast, they said.
Lord Justice Davis said: “The clear conclusion of both members of this court is that, viewed overall, these claims are not realistically arguable.”
But Lib Dem education spokeswoman Layla Moran tweeted “the fight must continue”, adding: “It is outrageous that the Remain voice is missing from the ITV debate.
“It’s simply wrong of broadcasters to present a binary choice and pre-empt the decision of the people in a general election.”
And a tweet from the SNP called their exclusion “ridiculous”.