Monday 30th December 2013 by Andrew Trendell | Photos by WENN

Tags: Britney Spears

Britney Spears has been accused of lip-syncing her way through 'the majority' of the opening night of her concert residency in Las Vegas. 

The 'Toxic' star  began her two year, multi-million-earning run of shows this week (27 December 2013) at the Planet Hollywood Resort & Casino with her Britney: Piece Of Me show. Many of the audience (which included Katy Perry, Miley Cyrus and Selena Gomez) were left stunned by the high-octane show, however others were less than impressed. 

"The singer appeared to be lip-syncing for the majority of her performance,” wrote the Los Angeles Times. "That went for high-energy dance numbers such as ‘Womanizer’ as well as slower-paced ballads like ‘Perfume,’ for which Spears took a seat onstage."

Meanwhile, Mike Prevatt from Las Vegas Weekly added: 

Britney Spears may be the only "live" performer with the chutzpah to lip sync to a song where she used AutoTune.

— Mike Prevatt (@mikeprevatt) December 28, 2013

Check out a short clip of the show below, where Spears performs a short mega-mix of hits 'Toxic', 'Till The World Ends' and 'Work Bitch' - before thanking her audience members. The clip clears up any confusion over whether she would sing live at the shows - as she most definitely is not.

See the video below

The star has previously hinted that her Las Vegas residency may be her last stint as a popstar, and suggested that she may quit music when her Las Vegas residency ends in 2015.

"I might [retire], who knows... I may have two more kids and get married," she said in a recent interview with US publication, Extra. "I'd like to have more kids."

Below - Photos: the sad, lonely and terrified eyes of Britney Spears