The Prime Minister, who is a fan of rugby and cricket, is due to start his closing press conference at the G7 summit in Cornwall moments after the Three Lions kick off at Wembley in their first Euro match 2020 Sunday.
The referee will blow his whistle to start the match at 2 p.m., while Mr Johnson is due to walk past television cameras five minutes later.
His spokesperson admitted: “It seems likely there will be a clash, I’m afraid, but we’ll do our best. “
The PM, who as summit host could decide the date of press conferences, will instead have to address a very small TV audience as fans tune in to the men’s Group D clash of Gareth Southgate with the Croats.
The revelation will cast further doubt on the Tory leader’s claim to be a football fan.
He blundered at PMQs this week forgetting that Wales would appear in the Championship – just the third time in Dragons history they’ve been involved in a major tournament.
Mr Johnson wished “Scotland and England all the best”.
But he missed Wales before adding, after a brief pause: “… and all the local nations that might play. “
The PM, however, played football at Wembley.
As mayor of London in 2006, he briefly stepped onto the pitch for a ‘game of legends’ between England and Germany.
He ran head first at waist height against former Stuttgart defender Maurizio Gaudina, sending him tumbling onto the grass.