Work done by load in charging a capacitor

The energy stored on a charged capacitor is  0.5*Q*V  or  0.5*C*V²  .

BUT

what is the electrical work done by the supply as it transfers the charge to the capacitor?

I have heard two answers:

 
W=QV       and      W=0.5*QV

the first answer implies, i think, that energy is required to move charges against the already present charges on the capacitor plate. is this correct ?