The electric field in a region of space that has the same non zero potential throughout is

    zero
     constant
     increasing from positive to negative potential
     decreasing from positive to negative potential

The units of "electric field" are Volts/metre.
If the potential is constant, the difference in potential from one point to another that is a centimetre away is zero (0/0.01 V/m)

So, equally, a charged object (a ball of polystyrene, for example) that is gently released, will experience a force of zero Newtons in each direction (since the alternative units to Volts/metre are Newtons/Coulomb... yes, they are identical, with 1 V/m = 1 N/C). So it, too, will see no electric field trying to accelerate it in any given direction.

So, the answer is, "zero".


Regards