It's Mark's band for one-off shows, mostly promotional shows, sometimes a bigger ones like 09.09.09 Prince's Trust show. Stripped-down band which even forces Mark doing questionable arrangements of song for instance with Guy playing an awful synthesised accordion on "Done With Bonaparte". I guess that band is like 1000000 times less expensive to bring on stage than his regular touring band.
And to tell you the truth, I like that band more than his regular band. But I think I know the exact reason why I like this band more. Because whenever Mark plays with his "backup" band, the show almost always is being recorded professionally for television. So you can barely hear these guy having bad sound.
Mark's regular band, however, had its last live album back in 2006, which is laughable. They think you can just replace a live album with a recording of each show, but that honestly doesn't work. Not only because there's no picture, but mostly because live audio mix sounds dull compared with full live album production.