The following are from The Press Association.
Downton Joanne: Shirley's such fun
The Oscar-winning actress will appear in series three as Martha Levinson, the wealthy mother of Lady Grantham (Elizabeth McGovern), and has been over in England filming her scenes.
Joanne, who plays housemaid Anna, said: "We haven't worked together but I met her twice on set and she was absolutely lovely.
"She was amazing, everybody loved having her there. She was so much fun to have around, she's really fantastic."
The 31-year-old actress, who usually wears a dowdy maid's outfit in the hit ITV show, was partying at the Empire Film Awards 2012 and admitted she loved being able to dress up.
She said: "I love Anna, and I love playing her and I love my little maid's outfit, but any excuse to dress up and I'm all for it, definitely."
Leech: My moment with MacLaine
The Irish actor - who plays Branson the chauffeur in the hit ITV1 show - got starstruck when he filmed a scene with the Oscar winner, who will appear in series three as Martha Levinson, the wealthy mother of Lady Grantham (Elizabeth McGovern).
"I sat down and the first line I did with her, it came out as 'Blah blah blah' and she went, 'Darling I think you got that wrong'," Allen revealed.
"She's amazing. Lovely. And so down to earth, which was really brilliant. She arrived on set and she kind of just became part of the cast.
"It's one of those casts where everyone just gets on so well. It's like a big family and when she arrived she just got embraced into it and she went with it, and it was brilliant."
Allen said Shirley got on particularly well with Dame Maggie Smith, who plays Downton's matriarch, the formidable Dowager Countess.
He added: "They got on like a house on fire. They know so many of the same people, they were sitting there swapping stories. Just watching them, there are three Oscars sitting there in front of you, it's amazing."
And the actor insisted he wasn't worried about ratings, despite rival BBC show Upstairs Downstairs experiencing a dip in its new series.
"You can never really think about stuff like that. You can only go on the success you've had before, and given the success we had, we'd love to match it and better it. It comes down to the storylines and I think they're there this year and I think we can do it."