The end is nigh for Irish boyband Boyzone, as they release their last album and prepare to hit the road on their farewell tour. We speak to the band's Ronan Keating and Keith Duffy about how they came to the emotional decision to say goodbye, and how their late co-star Stephen Gately still holds a special place in their hearts.

The mind boggles at how challenging it must be to make the monumental decision to finally draw a line under a 25-year career.

Despite the neat and tidy round number of a quarter of a century well-served - delighting the world with their harmonious ballads and sing-along cover versions - Boyzone's resolution to call it a day was not as straightforward as it may seem to outsiders.

"It took us a while to get to this decision to be honest," confesses lead singer Ronan Keating.

"It's not something you can decide overnight, it's such a massive thing in our lives. It took us about six months of to-ing and fro-ing and making a decision that finally this is it.

"We're 25 years at it now - it's a good number."

He adds: "But we're not kids any more, you can't do this sort of thing forever, and we wanted to go out on a high.

"We wanted to go out on our terms, and this felt like the right time to do that."

It's clear that for Keating and bandmates Keith Duffy, Mikey Graham and Shane Lynch, who were part of the boyband alongside Stephen Gately until his death nine years ago, the time is right to mark the end of a successful career, which saw them nab four Brit Awards and two MTV EMAs among countless highlights.

For their millions of devoted fans, their impending final curtain moment is a bitter pill to swallow, although the band members themselves aren't feeling low about it. Not yet, anyway.

"At this moment in time, it's still very distant for us, so we're not dwelling on it at the moment," Duffy explains.

"I'm sure as the date of the last show becomes closer to us, we're going to start getting a little bit worried, sad, emotional."

And how could they not, considering all that time spent together?

Boyzone was formed in 1993 in Ireland by Louis Walsh and, despite a hilariously misguided TV debut on RTE's The Late Late Show where they danced haphazardly in front of a bemused audience, they went on to score numerous number one singles and albums in both the UK and Ireland.

The group, Ireland's cleaner-cut answer to Take That, released a plethora of hit original songs, including Picture Of You, So Good and A Different Beat, as well as popular cover tracks such as Father and Son, Words and Love Me For A Reason.

After spending the best part of the 1990s riding high they split in 1999 amid group tensions, but reformed in 2007 and went on to embark on a well-received reunion tour with later plans to release new music.

It was a happy comeback for the band as they sold out venues across the UK and Ireland, but they were hit by tragedy when Gately died in October 2009.

Gately was 33 when he died at his home in Majorca from a congenital heart defect, sending shockwaves through the group and their fanbase.

But from the sadness came a somewhat bittersweet positive, Duffy reveals.

"I think the loss of Stephen made us all wake up a little bit and realise how important we are to each other and how important we have been in the memories of our lives together," he notes.

"There's nobody else in the world that I could reminisce about my life to than the boys because they were there for all of it - the good, the bad, and the ugly.

"All our success we celebrated together. Every time that phone rang and we were told we just went number one, or we sold our tour or whatever, it was always those memories were spent together."

He adds: "I think we realised how important we are to each other through all those things, and now as older guys and more mature men I think we embrace that now.

"We embrace the fact that we have that camaraderie, that brotherhood, that friendship, and we're very blessed to have good friendship."

Gately - fondly referred to by the guys as Steo - is, of course, part of their final album. His recognisable vocals are heard on a track called Dream, a reworking of a demo he recorded in 2002.

"It kind of happened by accident," Keating says, shedding light on how the poignant addition came to be.

"We were making the record, we were in full flow, and in the process a producer that Stephen wrote with about 16 years ago, was clearing out boxes and found this old demo tape of a writing session that they'd done together, and that tape, and basically sent it in to us.

"He sent it into the label, and they played it to us, and we were just blown away.

"We were like, this is fate. So we went into the studio and we pulled the track apart a bit, and made it into a more contemporary feel with our vocals, and rewrote the lyrics so that it worked."

"We kept Stephen's original vocals and it's just been perfect - he always wanted the last word. We loved that about him and it's the last track on the album.

Looking back at their time in the band, particularly those times with Gately, is a joyous walk down memory lane for the singers, now aged between 41 and 46.

Asked about their favourite moments from their time in the spotlight, Keating considers for a while, before answering: "I would say, for me, 2007 to 2009, the last tour we did with Steo was pretty magic.

"It was a magic time in Boyzone. We kind of found a comfort between ourselves, an understanding with each other. We'd grown up.

"We were kids the first time round, so we didn't really know what we were doing or who we were. So, for me that was the best time in Boyzone, definitely."

The inevitable question is - is this really the end for Boyzone? Will there ever be a comeback, years down the line?

They did, after all, split once before.

"We can't even go there," insists Keating.

"This is huge, it took us a long time to make this decision.

"It's an emotional decision, it's a business decision - there are lots of different decisions that we had to make that all came to this. And we can't think past it.

"It's going to take a year. The tour doesn't start till January, and then it will go all the way through into summer.

"We don't even know when the end date is, but we've got to focus on that for now."

- Boyzone's final album Thank You and Goodnight is out November 16. Their farewell tour of UK and Ireland kicks off in January.