A furious row has flared after it was confirmed that David Cameron and UKIP MEP Nigel Farage are scheduled to appear in a live referendum event on British TV less than three weeks before polling day in the EU referendum.
Vote Leave, the officially designated anti EU campaign, has reacted angrily to the decision, accusing the commercial broadcaster ITV of allowing Downing Street to choose the Prime Minister's opponent.
ITV has now been warned by the official Leave campaign that it faces consequences for its future after scheduling the debate between UKIP leader Farage and Cameron in the run-up to the EU referendum on 23 June.
Vote Leave is incensed that Farage was invited to take part in the debate instead of Michael Gove, a cabinet minister, or Boris Johnson, a former London Mayor and potential successor to Cameron if the UK votes to exit the EU.
Farage is arguably the most prominent anti-EU campaigner in the country but is not directly connected to Vote Leave, the officially designated anti EU campaign group run by Johnson and Gove.
Johnson has said he is willing to debate Cameron head on but Downing Street is thought to be determined that Cameron is not seen directly debating his fellow Tory colleagues as they fear that would enflame internal tensions in the party - and could backfire on the Remain campaign.
Cameron is widely expected to be forced to resign if he fails to win the referendum with Johnson, whose term as London Mayor ended last week, thought to be most likely to take his place.
The row flared after ITV announced it would hold an hour-long live programme on June 7 in which Cameron and Farage would in turn answer questions from a studio audience of around 200 people.
UKIP has already lodged a complaint against the BBC after it accused the state broadcaster of excluding Farage from participating in a live TV debate on Brexit two days before the referendum.
On the issue of TV debates on Brexit, Denis MacShane, the UK's former Europe minister, told this website, "Farage is a one pony politician. I do not know who is best able to speak for Leave and Remain. It is a very tricky question for the broadcasters."
Matthew Ellery, of the Get Britain Out campaign group, said, "Personally, I'd love to see Dan Hannan (a Tory MEP) debate with the Prime Minister. He makes a positive message based on increased trade and democracy after Brexit and the Prime Minister wouldn't have a chance."
Meanwhile, a vote for Brexit would threaten the security and sovereignty of Gibraltar, UK foreign secretary Philip Hammond has said.
Separately, Italian finance minister Pier Carlo Padoan said he was very worried about Brexit "not only for the immediate damage that can come to the U.K economy and the European economy, but also from the fact that this could be taken as an example of leaving Europe by other countries."
Elsewhere, the leader of the UK Conservatives delegation in the Parliament stormed out of an interview on the issue of Brexit.
Ashley Fox was asked why he would not debate the EU referendum in a "blue on blue" exchange with a pro-Brexit Conservative MEP. Fox told BBC South West political correspondent Martyn Oates he would "not play that stupid game".
Following the walkout, Conservative press officer Robert Taylor was heard to tell the production crew they had been "a bit naughty."