Arsenal boss Arsene Wenger and Manchester United manager Jose Mourinho clashed at UEFA's coaching conference last week.

Marca says an altercation came right at the start of the meeting where the latest act of petulance between the pair is alleged to have taken place.

Before Sir Alex Ferguson's opening address, Mourinho was rushing into the conference room where his other managers had assembled to listen to the legendary Scot.

As the current Manchester United boss looked for a seat he spotted a space near Paris St-Germain boss Unai Emery and Real Madrid coach Zinedine Zidane.

He asked if he could sit there but quick as a flash the response came from Wenger who has sitting nearby: "It is not possible."

The incident caused unease at the conference with those nearest pretending they had heard nothing while others are said to have stifled laughter.