British singers Charlotte Church and Rebecca Ferguson have rejected invitations from US President-elect Donald Trump's team to perform at his inauguration next week, they said in separate statements on Tuesday.

The rejections follow other apparent snubs by celebrities including Elton John, whose publicist denied in November that he would be performing at the event after an economic adviser to Trump had said that he would.

"@realDonaldTrump Your staff have asked me to sing at your inauguration, a simple Internet search would show I think you're a tyrant. Bye," wrote Church in a tweet she concluded with derogatory emojis.

Tom Barrack, a longtime friend of Trump who is organizing the January 20 event, brushed aside suggestions that there would be a lack of star power at the January 20 festivities.

Barrack told reporters that Trump himself was "the greatest celebrity in the world" and that the inauguration committee was aiming for a "much more poetic cadence" rather than "a circus-like celebration that's a coronation."

Trump's inauguration committee did not reply to requests for comment about Church and Ferguson.

Classical crossover singer Jackie Evancho, who rose to fame as a child performer on the TV show "America's Got Talent" six years ago, has confirmed she would sing the US national anthem at Trump's inauguration.

Church, who also began her career as a child classical singer, has spoken out in recent years about her left-leaning political views, and posted multiple tweets during the 2016 campaign criticizing Trump.

Ferguson, who gained prominence as a runner-up on the TV talent show "The X Factor" in 2010, said on Tuesday she too had refused to perform at Trump's inauguration because her choice of the song "Strange Fruit" was rejected.

The anti-racist song, which has been performed by the likes of Billie Holiday and Nina Simone, protests against the lynching of African-Americans in the South in the early 20th century.

"I requested to sing 'Strange Fruit' as I felt it was the only song that would not compromise my artistic integrity," Ferguson said in a statement.

"As music is so powerful, I wanted to try and help educate the people watching of where division and separation can lead to if not corrected. My aim was not to cause contention," she said.