Hollywood star Emma Thompson has told how she hopes to "manage the fear" and avoid nausea when she returns to the London stage in a musical production of Sweeney Todd.

The Oscar winning actress will star in the show at English National Opera's (ENO) London Coliseum, alongside Welsh opera singer Bryn Terfel.

Terfel, 48, will play the eponymous Fleet Street barber who murders his customers while Thompson, 55, has signed up as landlady Mrs Lovett, who disposes of his victims by baking them in pies.

The Saving Mr Banks actress will tread the boards in London for the first time in more than 25 years, with 13 performances next year.

Both Thompson and Terfel performed Sweeney Todd with the New York Philharmonic in a handful of critically acclaimed shows in Manhattan in March.

The Nanny McPhee and Howards End star admitted that she had been terrified when she took to the stage in New York.

"I've never been so frightened ever. What I'm hoping for is a slight improvement," she told a London press conference, "no nausea, no actual nausea.

"If I could manage the fear without the nausea I will be really happy."

Thompson last performed on the London stage in 1989, in a production of Look Back In Anger which was directed by Dame Judi Dench.

She said that she wanted to avoid "pointless" thinking about the time gap.

"You've really got to keep doing different things, flinging yourself and leaping into the dark otherwise you get a bit samey and people get bored," she said.

Asked if she was exercising her vocal cords by singing in the bath, she said: "I haven't had a bath for some time because I'm trying to conserve water. But I do sing in the shower."

Directed by Lonny Price, the Stephen Sondheim and Hugh Wheeler musical is the first in a partnership to bring musicals to the Coliseum, as part of plans to secure the financial future of the organisation, which has seen its annual public funding slashed by almost a third.

Thompson last performed in a musical in London in 1985, when she starred with Robert Lindsay in a West End revival of Me And My Girl.

Asked if she would reprise the role, she said: "Not Me And My Girl because I did that for 15 months and became clinically depressed.

"I think it was the effect of having to be so cheerful."

But she hinted that she would consider a longer run of Sweeney Todd or another West End musical if the show was a success, saying: "I would love to, I'm sure that will happen."

She told how her mother - the actress Phyllida Law - convinced her to take the plunge in New York in the "revolutionary piece about poverty and deprivation".

"I was in the back garden and my mum came, and I said 'I've been asked by the New York Philharmonic to do Sweeney Todd with Bryn Terfel' and she said, 'Oh my dear you simply must do it' and so I did."

Thompson said that it had been "magical" to use different "muscles" by performing in front of a live audience and that taking to the London stage was "like a dream come true."

Bass-baritone Terfel said that the musical was "undoubtedly operatic" and that Thompson had been "mesmerising" and "brought tears" to the eyes of the "die-hard instrumentalists" during rehearsals.

Sweeney Todd is thought to have made his first appearance in a 19th Century "penny dreadful". The Stephen Sondheim musical, which made the story popular, received its world premiere on Broadway in 1979.

It was famously adapted into a 2007 film by Tim Burton, starring Johnny Depp and Helena Bonham Carter.

Michael Grade, whose GradeLinnit Company is developing musicals with the ENO, said that he wanted the show to be one of the "great musical events in this great city in the coming year."

"Audiences, with good stories well told and great music, really don't make the distinction between musicals and the opera", he said.

ENO artistic director John Berry said that musicals would be staged in addition to the company's usual programming and would not replace opera.

:: Sweeney Todd: The Demon Barber Of Fleet Street, A Musical Thriller runs for 13 performances at the London Coliseum from March 30, 2015 with tickets from £10 to £125.