Johnston, who has played psychologist Grace Foley since the show started in 2000, told BBC Press Office: “I shall miss working with them all, I shall miss Tara [Fitzgerald]. I think Tara is fantastic and I loved doing scenes in the lab with her, I’d sit and look at how beautiful she was – she’d have died if she’d known, and such a beautiful person too.”

She added: “The crew were fantastic as well and they have been more of less the same crew since we started. I am really looking forward to it going out – to see how it is received.”

Discussing the show’s final episode, Johnston commented: “I will always remember it because even though we filmed it second, I had a sense of it being the end. The final scene under Waterloo bridge was fantastic. It is such a great episode and I love the shots of Boyd walking through London, walking to meet us. A great performance from Trevor, from everyone in fact.”

Series 9 begins at 9pm on Sunday 13th March.