With voters set to decide between throwing off Brussels rule or accepting Mr Cameron”s much derided EU membership renegotiation on 23 June, the BBC has unveiled plans for three major debates.
The main one will be “a Question Time special” on 15 June hosted by David Dimbleby with eight days to go with a head-to-head between two representatives put forward by the Remain and Leave official campaign groups.
While Mr Johnson said over the weekend that he does not want to take part in any TV debates it is understood that he is already coming under pressure to take on the role from Tory MPs and other Brexit campaigners.
Meanwhile Downing Street has said that Mr Cameron, who has previously expressed an interest in taking part in the debates, has not ruled anything out at this stage.
A spokeswoman said: “He hasn”t made a decision yet.”
It means that the future of the UK as an independent nation or one tied to European bureaucracy could come down to a clash between two men who have been friends since they attended Eton together and both later belonged to the exclusive hell-raising Bullingdon Club at Oxford University.
Already cracks in their old friendship have risen to the fore with the Prime Minister”s furious reaction to the London Mayor”s decision to back a Brexit having previously advised people he was “not an outer.”
The decision provoked an angry tirade by Mr Cameron against his old school and political friend in the Commons on Monday.
If Mr Johnson, who is believed to be desperate to be the next leader of the Tories, sticks to his original plan not to take part in the debates it is understood that Ukip leader
Nigel Farage is many people”s favourite to take on Mr Cameron.
The importance of head-to-head debates was highlighted in the Scottish independence referendum where the first was crucial in persuading Scots to stay in the UK when former Labour
Chancellor Alistair Darling took apart the then SNP leader Alex Salmond over his currency plans.
The BBC plans to open up its EU referendum debates with an event in Glasgow hosted by Victoria Derbyshire on Thursday 19 May aimed at younger voters.
Then after the head-to-head Mr Dimbleby will be joined by Mishal Husain and Emily Maitlis, live at Wembley Arena for the BBC”s biggest ever campaign event where thousands of voters will be invited to question representatives from the Leave and Remain camps on Tuesday 21 June.
Debates are also expected to be announced by Channel 4, ITV and Sky.