The longest standing rock group from the British Isles that is still performing and that still has all its original band members is U2 (1976-the present)
Dave Phoenix Farrell is the longest longest standing bassist of Linkin Park. He has also played bass for the band The Snax.
Rolling Stones
flex band
Kaleidoscope - UK band - was created in 1967.
The Outlaws - UK band - was created in 1960.
Perfume - UK band - was created in 1993.
Halo - UK band - was created in 1999.
Witness - UK band - was created in 1997.
Witness - UK band - ended in 2004.
Salem - UK band - was created in 1980.
Halo - UK band - ended in 2004.
Tempest - UK band - was created in 1974.