We present the discovery of a new gravitational lens system with two compact radio images separated by 0.701 \pm 0.001 arcsec .
The lens system was discovered in the Cosmic Lens All Sky Survey ( CLASS ) as a flat spectrum radio source .
Both radio components show structure in a VLBA 8.4 GHz radio image .
No further extended structure is seen in either the VLA , MERLIN or VLBA images . Hubble Space Telescope ( HST ) WFPC2 images in F555W and F814W show two extended objects close to the radio components , which we identify as two lens galaxies .
Their colours and mass-to-light ratios seem to favour two late-type spiral galaxies at relatively high redshifts ( z _ { d } \ga 0.5 ) .
Faint emission is also detected at positions corresponding to the radio images .

A two-lens mass model can explain the observed VLBA structure .
The best fit model has a reduced \chi ^ { 2 } of 1.1 .
The relative positions of the VLBA subcomponents are reproduced within 0.08 mas , the flux density ratios within 0.19 .
We also reproduce the position angle and separation of the two VLBA subcomponents in A and B within the observational errors , which we consider strong evidence for the validity of the lens model .
Moreover , we find a surface density axis ratio of 0.74 ^ { +0.10 } _ { -0.12 } for the primary lens ( G1 ) , consistent with the surface brightness axis ratio of 0.69 \pm 0.15 .
Also , the surface density position angle of ( 4.9 ^ { +28.2 } _ { -22.4 } ) ^ { \circ } of G1 compares well with the ( -6 \pm 13 ) ^ { \circ } position angle of the surface brightness distribution .
The errors indicate the 99 per cent confidence interval .