Alphabeat, Westlife enter top ten

Duffy has extended her reign over the singles chart, making it four weeks at the top with 'Mercy'.

H 'two' O and Nickelback hold steady at two and three respectively, while OneRepublic rise from eight to four with 'Stop and Stare'.

R&B singer Taio Cruz charges into the top ten, taking fifth place with 'Come On Girl', while Danish pop outfit Alphabeat jump from 23 to seven with 'Fascination'.

Meanwhile, Westlife are forced to settle for a number eight placing with 'Us Against The World'. If the single fails to rise in future weeks, it will become the boyband's lowest-charting release to date.

The top ten UK singles in full:

1. (1) Duffy: 'Mercy'
2. (2) H 'two' O ft. Platnum: 'What's It Gonna Be'
3. (3) Nickelback: 'Rockstar'
4. (8) OneRepublic: 'Stop and Stare'
5. (11) Taio Cruz ft. Luciana: 'Come On Girl'
6. (4) Basshunter: 'Now You're Gone'
7. (23) Alphabeat: 'Fascination'
8. (40) Westlife: 'Us Against The World'
9. (12) Flo Rida ft. T-Pain: 'Low'
10. (7) Rihanna: 'Don't Stop The Music'

> Did Duffy do the double? Click here for the album chart top ten!