According to the News of the World, Charlie Simpson, Matt Willis and James Bourne have been locked in talks over the past few weeks to reach a deal.
A source said: "James is the only one of them that doesn't need the tour. He's got a new solo album and a West End musical in the pipeline while the other two don't have much going on and have spent the fortune they made with the band."
Bourne wrote on his Twitter page: "I'll f**king get up and do it any time, any day, anywhere."
The band sold three million albums before they split up in 2005.