MARGUERITE Porter is determined to take part in Sunday’s Summer Gala at the Grand Opera House, York, despite damaging her knee.

Usually, the former Royal Ballet principal ballerina from Doncaster busies herself with overseeing the song-and-dance extravaganza every two years in aid of the Yorkshire Ballet Summer School, but this weekend she will defy any lingering pain to dance with Christopher Tudor.

The reason for such resolve is her desire to perform for her ailing husband, the actor Nicky Henson. “It means everything to me to do this performance,” she says. “When you live with a disease for so many years, you have to have something to look forward to…and Nicky is really looking forward to this.

“His favourite song, even before he met me, was Cole Porter’s Night And Day – such a lovely song – so Alexander Hanson will sing it for us and then I’ll come on and do a pas de deux with Christopher, who teaches with me at the summer school.”

Marguerite and her fellow former ballet dancer started rehearsing their routine seven weeks ago. “We’d learnt it and were running it twice a week until this injury occurred. Now it’s just a question of getting through it on the night, though I’d like to do it once before doing it on stage,” she says.

She may well be defying discomfort to do so. On the day of this interview, she had a hospital appointment for an MRI scan that would reveal the extent of her injury.

“I’m fine, I’m okay, but I’m hobbling about a bit. Once I’ve been to the hospital I’ll know what damage I’ve stupidly done to myself,” she says. “I’ve iced it and rested it, but they think it’s a torn cartilage.”

The injury was sustained after Marguerite, 63, had been asked to play Lady Capulet in a charity gala for a new cancer charity at the Coliseum in London with dancers from the Royal Ballet and Bolshoi Ballet and Canadian ballerina Lynn Seymour as Lady Montague.

“I knew it was a step too far, with me doing my own gala already, but I was persuaded to do it and went to my first rehearsal of the week where this young man showed me very dramatically what to do,” says Marguerite. “He pushed me quite hard and quite fast and unfortunately I fell in a dying swan position and I felt something go in the knee.

“But as ever, as a dancer, I just thought ‘keep it going’, so I did three more days of rehearsals and it was only when I couldn’t walk that I decided I must do something about it.”

Whatever the diagnosis, Marguerite will still perform. “There’s no question; I will do it as I have everything organised,” she says.

“There’s a wonderful physiotherapist in York who will help me through the week, and even if it’s a torn cartilage, I’m going to have an anaesthetic shot to get me on stage.”

Marguerite Porter’s Summer Gala evening takes place at the Grand Opera House, York, on Sunday at 7.30pm. Box office: 0844 871 3024 or grandoperahouseyork.org.uk