Popular Irish boyband Westlife are reuniting and recording a new comeback record - but here's why Brian McFadden is not in the lineup.

Westlife have announced their return to the spotlight after a six year hiatus.

The music group will be launching a comeback song written by none other than Ed Sheeran.

A source told the Irish Sun that the deal with Universal is "signed, sealed and delivered and it’s definitely happening — and it absolutely does not include Brian McFadden."

According to the outlet, music boss Simon Cowell passed on the option to sign Westlife as a four-piece band, as he was "only interested" if McFadden was involved.

Westlife are making a comeback but not as their original line-up. @danwootton explains why the band are returning as a four-piece without Brian McFadden...#Lorraine pic.twitter.com/N7xtLbdWZB

— Lorraine (@lorraine) September 24, 2018

“The other guys have been lined up to return to the studio and record some new songs and tour dates have even been organized, so it’s definitely going ahead this time," the source teased.

“There’s been a lot of speculation, but this time it’s a done deal and contracts have been signed.”

“Simon wanted a Westlife reunion but only with something extra to bring fans back. That meant Brian and his unpredictability. It would give the Westlife reunion the tension it needs," the source added.

If reports are to be believed, the remaining quartet have already recorded new material alongside Ed Sheeran.

Exciting News For Westlife Fans ???#ShowbizRoundup #Westlife #Reunion pic.twitter.com/QLYDhfk1oA

— Xposé (@Xpose) September 24, 2018

The band was formed in 1998 including Brian McFadden, Nicky Byrne, Kian Egan, Mark Feehily, and Shane Filan. Originally managed by Louis Walsh, they were signed by Simon Cowell in the UK, who helped launch them to popular acclaim and chart-topping success across the globe.

McFadden, whose sister is Celtic Woman star Susan, left the group in 2004 to focus on his solo career. The remaining members continued touring and recording until 2012.

Ed Sheeran doesn't use Twitter anymore so I'm going over to his Instagram to ask if there's any truth in these rumours #Westlife #WestlifeReunion pic.twitter.com/mU0E2KqGee

— Hema Malik (@Hema_ByrnesArmy) September 24, 2018

Over their lengthy career, Westlife sold over 40 million studio albums and 55 million records overall worldwide.

Are you excited about the Westlife reunion? Let us know in the comments below!

Read More: CIA used a Westlife song to torture terrorist suspects

Read More: Ed Sheeran explains why you should all live in Ireland