Sheridan Smith and Jill Halfpenny took major acting honours at London’s Olivier theatre awards on Sunday.

Former EastEnders star Halfpenny won the Best Performance in a Supporting Role in a Musical for her part in Legally Blonde – The Musical, while the star of the show, Gavin & Stacey’s Sheridan Smith, won the award for Best Actress in a Musical.

The tearful actress thanked ‘everyone who let a chav play an American rich girl’. Speaking backstage, she paid tribute to her family including her father, Colin, who accompanied her down the red carpet.

She said: “When they said my name my dad started crying and that just started me off. I’m a complete chav, I’m just a little scrubber from Doncaster and I can’t believe I’ve just won an Olivier award.”

Veteran actress Angela Lansbury made her debut on stage at the Theatre Royal in Drury Lane as she paid tribute to American composer Stephen Sondheim.

The 85-year-old, who was born and bred in London, but has spent most of her career in the United States, returned to the capital for this year’s awards which were held in the Covent Garden venue. She joined theatre producer Sir Cameron Mackintosh on stage to present the Society of London Theatre’s Special Award to Sondheim.

The British-born actress said she presented the award with ‘great, great pride and deep affection’.

Sondheim, whose hits include West Side Story, A Funny Thing Happened on the Way to the Forum and A Little Night Music, received a standing ovation. He spoke about the influence of British theatre on his career and paid tribute to Mackintosh, saying he was a man ‘whose friendship I treasure, who is the best producer I’ve ever worked with and one of the best people’.

A revival of Terence Rattigan’s After the Dance picked up the first prize of the night.

Presenting the award for Best Revival, Sir Patrick Stewart admitted revivals had been something of ‘a dirty word’ in the past, but said the nominated plays represented the ‘extraordinary diversity of London theatre’.

Accepting the award, the play’s director Thea Sharrock joked: “I’m a huge Arsenal fan so I’m not used to winning”.