Stars of stage, screen and politics have praised a new "bloody" and "intense" West End version of Macbeth.

James McAvoy, who has appeared in hit films X Men and The Lion, The Witch And The Wardrobe, stars as the lead role in the modern take of one of Shakespeare's darkest plays which opened last night.

Claire Foy, perhaps best known for her role in Little Dorrit, acts alongside him as Lady Macbeth, one of Shakespeare's most famous female characters.

Former spin doctor Alastair Campbell and actors Rafe Spall, Toby Jones and Jason Flemyng were among guests at the Trafalgar Studios on London's Whitehall.

The performance was met with a standing ovation, with McAvoy's proud wife, Anne-Marie Duff, the first to rise to her feet, swiftly followed by the rest of the audience.

The play is director Jamie Lloyd's first in a season called Trafalgar Transformed.

He said they would be "a season of politically-charged power plays on the doorstep of Whitehall", accompanied by workshops and masterclasses aimed at school groups.

The stark stage sets the scene for a war-torn Scotland of the near future, smothered by toxic fog.

According to the programme notes, the play takes place after years of financial and environmental disasters in a divided United Kingdom.

Lloyd said: "It's an apposite, urgent play for today, and that's why I don't want it to be set in period. I don't want the production to be a reflection of a time long past, I want it to resonate here and now."

There was widespread praise for the play, which was also attended by comedian Stephen Merchant and Downton Abbey actor Hugh Bonneville.

Merchant said: "I loved it. I loved the bloodiness of it, the passion and the youthfulness of it, which was a nice take on the play."

There was so much gore, in fact, that the floor had to be mopped between the first and second halves.

Bonneville simply said: "James McAvoy is a brilliant actor, full stop."

Spall said: "I thought it was extraordinary. Both James McAvoy and Claire Foy gave timeless, peerless performances."

Singer Beverley Knight said: "Only Shakespeare himself could come up with the words to describe what I've just seen. I'm at a bit of a loss.

"It was so spellbinding, so intense, incredibly gripping.

"I thought I knew the play but now I'm seeing it with fresh eyes. It was absolutely unreal."

Campbell gave his seal of approval on Twitter, writing: "James McAvoy superb Macbeth. Sounds alarmingly like @georgegalloway at times.

"Claire Foy tops as Lady M."

Part of the transformation element has seen the auditorium reconfigured for Macbeth so that more than 70 audience members are seated on the stage.

Design is by Soutra Gilmour, who won the Best Design award at last year's Evening Standard theatre awards.

McAvoy, who has gone from starring in film The Last King Of Scotland to the production known as "the Scottish play", was last on stage in 2009. Three Days Of Rain, at London's Apollo Theatre, was also directed by Lloyd.

The play, running until April 27, is almost sold out, and the remaining tickets are likely to go quickly after the first reviews in Saturday's papers applauded the gritty, dark production.

It was given four stars by the Daily Telegraph, with Charles Spencer saying it "packs a powerful punch".

He noted the dank and dismal setting, writing that the Macbeths' castle "is more squalid than a student flat during the Edinburgh Fringe" and praised McAvoy's "commanding" performance throughout.

Spencer described the production as "gripping and genuinely startling" - though he had a slight gripe about its running time of nearly three hours.

Paul Taylor in the Independent also awarded Macbeth four stars, saying McAvoy gives a "gripping, no-holds-barred performance" that will encourage his young fans to explore Shakespeare.

"Pac-a-mac ponchos" are advised by Taylor for those in the front rows on stage, due to the blood-splattered nature of the play. There are times it goes a little over-the-top, according to Taylor, but also moments of "extraordinary thematic penetration".