What made you want to be part of this drama?
I have always been obsessed with Barbara Windsor and her career, and when I read the script it just grabbed me. It was so different from anything I have read. It was so brave, and I just loved that Barbara had allowed them to do something like this about her life - I think she has been very brave too.

I was unaware of her Broadway stardom and her history at Ronnie Scott’s, so it was enlightening to find about that stage of her life, that I was playing. I was also very curious about her love life and what made her the woman she was. The fact it's partly theatre-based, and a film that was going to be playing on television, made it feel very special from the start.

Did you do any research for the role?
I restrained myself from re-reading her biography, but to refresh my mind I wanted to go straight to the source, straight to Miss Windsor. I wanted to figure out what kind of lady she was, and she was very giving - Barbara is very generous with her life in that sense. From the moment we sat down and started talking I channeled who she is, where she comes from. She gives you it all and is very innocent, and I wanted to keep that innocence in my performance.

Did you study any of Dame Barbara’s work, interviews before starting the role for mannerisms etc?
Yes, lots of her interviews and also whilst sitting with her. It was a very bizarre feeling for me. You watch someone on television your whole life, and then all of a sudden you are having tea and cakes with them at their house, learning how to play them. Barbara has a very cheeky little-girl way about her and I tried to embody that and let the rest fall into place. I think we managed it. It was about watching her - she is such a larger-than-life character and so cheeky, and once you get that then all of the other stuff, the emotional stuff, comes through in the script. There’s a lot of stuff she says with her eyes which makes her so great, she is so playful and she has an amazing wit and humour, you have got to keep up with her! To believe that she is going to be 80 this year is unbelievable. 

Was Barbara there when you auditioned?
She wasn’t thankfully! Could you imagine how nerve-wracking that would be? I was very nervous apparently, but I went in and kind of demanded the role (laughs); but in a way of I came in as Barbara doing a Carry On film - I had the hair, the walk and the laugh!

There are certain jobs that are for you and this just called out to me. I had heard about something being developed, and I had this flashback of meeting Barbara when I was 15 years old at the Baftas with my dad. She sat behind me and I did this big giggle and she turned and said “oh you should play me one day” and my dad and I had this moment of, wow that would be amazing... and 15 years later it has happened. I tell that story quite a bit, but it did happen, and you know what? This is my role and without being arrogant something felt right, some things are meant to be! I hope my performance shows that, but I was just super excited to be playing such a British icon.

So did you know Barbara well before you took on the role?
No not at all. I had met her just the once at that event (Bafta). It’s funny when you meet someone like that, you think you know her because she is such a star. She is such a star and so approachable, she is a real East End girl as am I, and you feel like you can relate to her instantly. That’s the beautiful thing about this film, that you learn so much about her from the beginning of her life. You think you know someone and then you sit down and have tea and cake with them and it is just bigger and better than you can possibly imagine. It was a dream come true to play Barbara.

It was something for me to have a year out of work to go and have a baby and then have this sort of turnaround and come back to do something like Babs, something so strong for the BBC. I am so proud of it and I am so gracious and thankful that Barbara was very happy it was me. She was so gracious and giving throughout the shoot. She was very encouraging she would say something like “don’t forget this is your job, it’s my life but it is your job”. Stuff like that. She is just inspirational.

What was your biggest challenge when taking on this role?
For me, probably the jazz hands, the singing and the showgirl stuff. Although I have been in theatre and I have other stuff like that, I have never really combined the two. I just really wanted to get it right, get her voice right and it was actually more finding that confidence to just belt it out on stage and to be fearless and flawless as she was. She always says “I wasn’t a good dancer or singer but put it altogether and it’s ok” but she actually was great and she did sound fantastic and she did capture all those people’s hearts when she sang on stage. I think that for me it was getting that right and hopefully I did. It was getting that right and getting that flawless innocence because she really didn’t know how good she was and she was achieving that naturally without having to go to the studio to perfect it with autotune and stuff like that. It was staying true to her performance.

So did you enjoy stepping back and wearing the costumes of that time?
I loved it! It was like a dream come true. All those outfits which set the scene for that era in east London. You know it was just wonderful, you just felt so glamorous. She was just a wonderful character to play, and for me, stepping into Barbara’s tiny two and a half sized feet was just such an honour, an unbelievable honour.

What do you think makes Barbara so iconic?
Well where to begin? Her look, her laugh, her brazen strong style of acting, the choices that she’s made, and, if you think about it, there isn’t anyone like Barbara Windsor who has stuck with her look and succeeded. Her shape, her bravery. I think she has been very ballsy at points in film history where you weren’t really allowed to do that, you weren’t allowed to show a bit of cleavage. I think she just made some seriously brave moves in a really innocent fashion.

What has it been like to work alongside Samantha, Nick and Zoe?
Sam and I clicked instantly. She has played Barbara before, she was very aware of keeping it fresh and she knew where she was at, whereas I was slightly more nervous  - it was a whole new territory for me, especially as I hadn’t worked for a year. She just guided me, she was so giving. We got on and we instantly became two naughty little sisters who were running around as Barbara Windsor and giggling, it was fantastic. I loved working with Sam, she was fantastic to watch and she is so amazing in this. 

Working with Nick was fantastic. He was slightly outnumbered by women at most stages in this film! I have known Nick since I was a baby.

Zoe is just the real deal. You know when you’re working with a great, and she was so lovely and just stepped into the shoes of Joan Littlewood, who she was playing. As a lot of it was shot in a theatre on stage, we sort of slipped into this method acting. It was brilliant. She is really powerful, Zoe. She has a real presence and you just end up staring at her and, really interestingly, I do believe that she just became Joan. I could feel that fear that Barbara may have had whilst shooting those scenes, that “oh god, this isn’t what I normally do”. Also how fantastic for someone to really believe in her and to drive her to a point where she was really out of her comfort zone.

This was a special job for me. I got to work with such fantastic actors and to play someone so wonderful, it is a dream come true, a dream role.

Babs, BBC1, Sunday, 8pm