Gravity, the band's upcoming eleventh LP, was produced in its entirety by Take That and Miley Cyrus collaborator John Shanks - the first time the Irish four-piece have worked with just one producer across a whole album.
"We'd wanted to work with him for a long time, but all his loyalty was to Take That and he didn't want to work with another boyband," group member Mark Feehily told DS yesterday afternoon.
"We'd been asking him and asking, but literally within moments of Take That deciding to go and work with Stuart Price, he said yes to us straight away. Afterwards he said he'd wanted to work with us for a long time, but he just couldn't do the Take That thing and the Westlife thing because they were too close."
However, Feehily's bandmate Shane Filan insisted that Shanks was not content merely to mimic his work with the Manchester manband.
"John created a sound for us in the same way he created a sound for Take That, a sound for Bon Jovi and a sound for all the other incredible artists he's worked with," he said.
"He created a sound for Westlife that we haven't had before - it's not a massive departure, but it's definitely a step up in terms of production."
Filan also revealed that the group is currently in the process of selecting 12 or 13 songs for the album's final tracklisting from a pool of 16, with all but "one or two" likely to be originals.
"The lead single 'Safe' is the most Westlife-sounding song on the album. It's kind of like the starting point for the album," Feehily explained, before Filan added: "There are different styles of ballads on there - some of them are really mellow and have really low-sung vocals - and there are lots of midtempo tracks too.
"There's a song I love called 'No One's Gonna Sleep Tonight' that's an uptempo dancey record, and another called 'Tell You I'm Dreaming' that's a bit like an Erasure track."
Westlife release new single 'Safe' on November 8, followed by the album Gravity on November 15.