In their home country Burke became known by winning the fifth season of the talent show The X Factor, which aired from August to December 2008 at the evening program of the TV channel ITV.
During the season, together with the other X Factor finalists took her on a cover version of the song Hero by Mariah Carey, who took three weeks number 1 in the UK charts in November 2008.
In the final show on 13 December 2008, she sat down with 58 % of the votes total of eight million viewers votes against the four -piece band JLS and singer Eoghan Quigg through and got a worth one million pounds sterling record contract with Syco Music / Sony BMG.
One day after the final, published in the week before Christmas in the UK Burke's debut single, Hallelujah, a cover of the same name hits by Leonard Cohen from the year 1984. Already before the finale who according to Simon Cowell, the creator of The X Factor 500,000 pre-orders received for the single. Hallelujah rose over Christmas at number 1 on the UK charts and was thus the Christmas number 1 in the UK. In the sales statistics of 2008, the song was also ranked number 1 in front of the X -Factor Community Hero Factory.
Then it took nine months to the completion of their debut album Overcome. In the week prior to publication in early October 2009 was released in advance of the song Bad Boys as a single, a collaboration with U.S. rapper Flo Rida. Even so they immediately jumped back to No. 1 on the charts in the UK and Ireland. The album was followed to the top of the charts and was also able to place internationally. Four other songs it still came afterwards in the British Top 20, with Start Without You they even had their third number-one placement.
In early 2011 Burke went on UK tour before they started on a new album with the work. Shortly before the release, she left the label by Simon Cowell and joined RCA to. In March 2012, she published there once the single Elephant in collaboration with DJ and producer Erick Morillo. The song reached # 3 on the UK charts. Two months later, appeared just before the album the song Let It Go, which, however, came only at number 33. The album Heartbreak on hold then came does not go beyond number 18 on the album charts and stayed only two weeks in the Top 75 Just a little later was announced Burke that she was working on an album for the U.S., whose focus again was to R & B to be.