Since it first appeared on our screens five years ago, the costume drama Downton Abbey has broken all records, pulling in an audience of 120 million in 220 countries and turning round the fortunes of ITV.

It even received the royal seal of approval this March when the Duchess of Cambridge visited its London studio.

So, you might have thought the producers wouldn’t begrudge its actors taking a few mementoes from the set when the sixth and final series finishes in December. However, I learn that cast members are piqued they have been banned from doing so.

‘When it’s over, it would have been nice to take a prop home with me from the set,’ says Penelope Wilton, 68, who plays Isobel Crawley. ‘But we’ve specifically been told we’re not allowed to do that.’

The ban has been introduced following comments made last year by her co-star Lily James, who revealed she tried to swipe items belonging to her character, Lady Rose MacClare. ‘I always want to steal my jewellery from the set because it’s so nice,’ Lily said.

‘It’s fake, but it’s good fake, so you can get away with wearing it. But I think they are on to me because there are a few things gone now.’

Wilton plays the widowed mother of Dan Stevens’ Matthew Crawley, who died in a car accident in series three’s Christmas episode.