De Sousa is to arrive in Salzburg on Thursday at the invitation of his Austrian counterpart, Alexander van der Bellen, but his official programme is mainly on Friday, with the opening of the musica festival and work meetings to be followed by a joint news conference with van der Bellen, as well as his attendance at a performance of Mozart’s opera ‘The Magic Flute’.

The meeting with van der Bellen – the left-wing head of state of a country governed by a coalition of conservatives and the far right - is preceded by what is described as a "brief meeting with the permanent representatives of the European Union in Brussels" - at a time when Austria has just taken over the revolving presidency of the European Council.

Among performers at the 98th Salzburg Festival is Portuguese soprano Ana Quintas, who is in the cast of a production of Monteverdi's ‘The Coronation of Poppaea’ that is to be staged on 12 August.