Matthew Feargrieve, a solicitor specialising in corporate and investment funds law, punched fashion designer Ulrich Engler “at least once” after he took a seat next to Mr Feargrieve’s wife.

Mr Engler told City of London Magistrates’ Court that he had moved from his second-row seat to a vacant front-row seat in a previous performance in Royal Opera House and decided to do so again.

He said asked Catherine Chandler if he could take the empty seat next to her and she said no, but admitted that she had not paid for it, so he moved into it anyway.

He removed Ms Chandler’s coat from the seat and put it on her lap and Mr Feargrieve then leaned over her and began hitting his shoulder, The Guardian reports.

Mr Engler was then arrested and temporarily banned from the opera house, though the case against him was dropped within weeks.

Finding Mr Feargrieve guilty of common assault, District Judge John Zani said he was confident that the events “occurred in the way Mr Engler recalled”.