You didn't tell the resistor values, we have to believe that they are chosen appropriately.
Provided they are, the microcontroller will be driven by an AC voltage (positive and negative cycles). Negative input voltage and current might exceed the µCs maximum ratings. You also loose the capability to observe the instantaneous input voltage over the full cycle.
I understand that "measuring peak voltage" means to sample the input voltage continuously and assume the highest value as peak value. That's not particularly accurate and sensitive to non-sinusoidal waveforms. If the current waveform is a sine, you should be able to achieve the intended 10 % accuracy.