The track is featured in a promo clip that sees an artist make portraits of the girl group.
The accompanying video will be used on the Big Reunion UK arena tour, which kicked off in Sheffield last night (May 3).
The track seemingly confirms the recording of new material by the 'C'est La Vie' group, who spoke about the possibility earlier this week.
Member Lindsay Armaou revealed that the group are in "a really good place" following their stint on the ITV2 series earlier this year.
She continued: "Our relationships with each other are all in a really good place again. We've been spending a lot of time together and it's good - it's really, really good."