It is difficult to move my car from rest smoothly in first gear.
The car begins to move, hesitates, then picks up speed normally.

Main dealer acknowledges 'slight hesitation when emerging from side roads' but claims this is a feature of the manual gearbox.

I am not convinced by this explanation; any ideas?

Could it be the Blue Efficiency gubbins? The throttle response appears damped at all speeds i.e. there is considerable movement of the pedal before the engine responds.