Atomic Kitten are an English pop girl group formed in Liverpool in 1998 whose current members are Natasha Hamilton, Kerry Katona and Liz McClarnon, with Michelle Heaton filling in for Liz at International shows.The band was founded by Orchestral Manoeuvres in the Dark (OMD) frontman Andy McCluskey, who served as a principal songwriter during their early years. Sugababes singer Heidi Range was included in the original line-up but was replaced by Hamilton. The group's debut album Right Now was released in October 2000 and peaked at number 39 in the UK. After four top ten singles, Katona quit the group and was replaced by former Precious singer Jenny Frost. "Whole Again" (recorded before Katona left), their next single, became their most successful single when it topped the UK singles chart and became the 13th best-selling single of the 2000s. The group re-released their debut album, with some tracks re-recorded with Frost's vocals. The album hit number one in the UK with the album going double platinum after selling over 600,000 copies in the UK.
Between 2002 and 2004, the group released a further two studio albums, Feels So Good (which also went double platinum in the UK) and Ladies Night, and a greatest hits album before announcing a break following their 2004 tour. To date the group have had three UK number-one singles: "Whole Again", the fourth-best-selling song of all time by a girl group; "Eternal Flame", a song originally recorded by The Bangles; and "The Tide Is High (Get the Feeling)", a song originally recorded by The Paragons and by Blondie. The group split up in 2004 after selling over 10 million records worldwide.
After making sporadic appearances in 2006 and 2008, it was announced that McClarnon, Hamilton, and Katona would reunite for the ITV2 series The Big Reunion, along with five other pop groups of their time—B*Witched, Five, Liberty X, Honeyz and 911. Frost was unable to take part in the comeback because of her pregnancy, but Hamilton has since confirmed that Frost would be welcomed back if she wanted to rejoin the group in the future.