With it, the Top 40 itself set its own record for the most chart-toppers in one year.

The group's single Keep On Movin' became the 31st single of the year to go to number one, which is one more than the previous highest total of 30, set last year.

Tightly controlled marketing has helped the number grow, as record companies put their efforts into securing a chart-topper the week it is released.

Ritchie: "Thrilled"

With eight more charts to come before the end of the year the list could grow further.

Five have already scored six top five hits but have missed out on number ones, often narrowly.

Band member Ritchie Neville said: "We're absolutely thrilled to eventually get our first number one this year.

"We would like to say a big thank you to our fans and the media who have supported us."

'Marketing getting slicker'

Five knocked rival boy band Westlife off the top slot, after just one week.

The high turnover of number ones in the charts this year has indeed been at the cost of longevity, with no single holding the position for more than three weeks - the first year that has occurred.

Westlife: One week at number one

Cynics with memories of The Beatles, Elvis Presley and even Abba, may claim that modern bands simply are not producing the goods to justify big sales of singles and successive weeks at number one.

The start of the year saw a massive turnover of singles at the top of the chart with 12 new number ones in as many weeks.

Chart expert Gennaro Castaldo of the HMV retail chain said: "The marketing is getting slicker and everyone is trying desperately to use sales in the first week of release to catapult singles to number one.

"Having a number one is still seen more than anything else as representing an artist's achievements and still holds a lot of kudos.

"Having singles success is also a catalyst for getting people to buy the album."

Sales drop after one week

Much of the marketing drive is focused on mobilising fans to buy a record within days of release, as sales generally tend to drop after the first few days.

Acts rarely go up to number one if they have not done so within a week.

Mr Castaldo said: "They reach the fans through fan clubs, internet sites and with masses of advance radio airplay - up to six weeks before release - to build up the demand.

"The media, representing the public at large, are often quick to condemn the turnover of records in the charts, saying it is some kind of conspiracy.

"But they also set great store by getting to number one, so if for any reason bands don't top the charts they are deemed to have lost their touch or have failed."

Mr Castaldo had good news for the latest chart-toppers.