Britney Spears’ eagerly-anticipated comeback single has reportedly been written by none other than Little Mix!

According to The Sun, the X Factor girl group are behind Brit’s new song 'Pretty Girls', which was originally recorded for their third studio LP but failed to make the cut.

[related]It’s thought that Spears will now release the the track as a collaboration with Aussie rapper Iggy Azalea, with a source telling the tabloid: “This is a huge coup for Little Mix.

“The song is really brilliant but the lyrics just didn’t end up fitting well with their own record. But Britney loved it and wanted to pick it up for her own album as soon as she heard it.”

They continued: “It’s amazing for them that Britney has decided to release it as her comeback single – and perfect timing given they’re about to release their third album.

“This will really help their profile in America. It’s a real sign that the girls have a big future as songwriters as well as pop stars.”

If proved to be true, 'Pretty Girls' will be Britney’s first single since 2013’s 'Perfume'.

Meanwhile, Little Mix have been busy teasing their new record, with the girls telling fans during an online hangout that it’s “nearly ready”.

We can’t wait!