Boris Johnson and Jeremy Corbyn will face each other later in the first TV debate of the election campaign.
The head-to-head between the Conservative and Labour leaders, hosted by news presenter Julie Etchingham, will be shown on ITV at 8 pm.
It comes after the Lib Dems and SNP lost their legal challenge to be included in the live programme.
They argued that their views would not be represented but judges ruled there was no breach of the Broadcasting Code.
The head-to-head is scheduled to be followed at 11 pm by interviews with party leaders, including Liberal Democrat leader Jo Swinson, reacting to the debate.
News presenter Julie Etchingham told BBC Radio 4’s Today programme that chairing the debate was a “hard thing to navigate if they won’t engage and debate with each other”.
Her role would then be to put specific points to each of them, she said, adding: “The best debates are when they debate and engage properly with one another.”
She said ITV had received hundreds of questions “across a whole range of subjects” from their viewers, so the broadcaster knows what questions the public wants answered.
On Monday, in London’s High Court, 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 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.