EastEnders: Anita Dobson returns as Angie Watts for anniversary ...

Anita Dobson has made a surprise return to EastEnders, reprising her iconic role as Angie Watts in honour of the show's 40th anniversary.

The actress, 75, who last appeared in the soap more than 37 years ago, played the landlady of the Queen Vic pub from 1985 to 1988.

Her character, Angie, returned to the pub to visit her daughter, Sharon Watts, as she drifted in and out of consciousness while trapped under rubble after an explosion during Wednesday's episode.

Dobson said she kept her return a closely guarded secret, telling only her husband, Queen guitarist Sir Brian May.

"It's been really hard because so many people that I'm really close to have said, 'oh are you going back?' because I've gone back to do the documentary, so it's been so hard not to say anything," she said.

"But I've been a really good girl, and I've kept my little mouth shut because I didn't want there to be any spoilers!"

Despite having been away from Walford for over three decades, Dobson said stepping back into Angie's shoes felt natural.

"She's always there at the blink of an eyelash. She's inside me, and she always will be," she explained.

"When I first put the costume on, it was like 'Wow'. It was very wonderful and weird at the same time."

She said working alongside Letitia Dean, who plays Sharon, again was "seamless" and "incredibly emotional in a lovely, happy way".

Chris Clenshaw, EastEnders' executive producer, praised Watts's "formidable" and "iconic" character, and said her return was a fitting tribute to the show's rich history.

"Since the very first episode, Anita instantly created a character that the audience adored and she not only shaped EastEnders into the show it is today but also had a huge impact on British television," he said.

Thursday's episode will be a special live edition of the show with viewers asked to vote to decide the romantic fate of Denise, played by Diane Parish.

In celebration of EastEnders' 40th anniversary week, BBC News will provide live coverage of the special episode on Thursday, 20 February. You can watch it on BBC One and iPlayer and follow along on our live page.