He told the latest issue of OK! magazine: ''I'm in if it's a five-piece. I'd probably be in even if it isn't.
''That being said, that's not on any calendar for the next five years.''
The 'Giants' trio have been eyeing getting Robbie and Jason back for what seems like years, and there was some hope when Gary said earlier this year that he thinks part-timer Robbie and Jason, 47 - who quit in 2014 - could return in 2022 for a ''greatest hits'' tour and possibly a record.
He said: ''I don't think anything we do with Rob is going to relate to like a big 25-year project.
''In fact, I'll tell you this for the first time, we're looking at 30 years.
''We're planning something to do for the 30-year all together. We're looking that far ahead, something big, maybe a new record, maybe a greatest hits with a big tour.''
Howard, 49, said then he would love to see the five of them back for good, but said he doubts it will ever happen.
He added: ''A five-piece would be incredible. Whether that ever happens or not, that's a different story. My gut's telling me no. I'd love it to happen.
''That's the nice thing, that we can all hope it will happen but, you know, no pressure on anybody to do anything.''
Gary - who announced a solo UK tour for 2018 - later admitted he'd given up hope on Jason rejoining the band.
He said: ''He didn't want creative involvement because we're day-to-day on this and he wanted to leave.
''This has been weird with the whole Jason thing. He'd told us for a while, 'I don't want to be in music anymore, I don't want to do this anymore', and we'd push, push, push.
''At the end of the day you've got to accept someone doesn't want to do what you're doing anymore.''
From 'Happy' to 'Banana Pancakes', these are soaked in positivity.