  Understanding the microscopic origin of the gate-controlled supercurrent
(GCS) in superconducting nanobridges is crucial for engineering superconducting
switches suitable for a variety of electronic applications. The origin of GCS
is controversial, and various mechanisms have been proposed to explain it. In
this work, we have investigated the GCS in a Ta layer deposited on the surface
of InAs nanowires. Comparison between switching current distributions at
opposite gate polarities and between the gate dependence of two opposite side
gates with different nanowire$-$gate spacings shows that the GCS is determined
by the power dissipated by the gate leakage. We also found a substantial
difference between the influence of the gate and elevated bath temperature on
the magnetic field dependence of the supercurrent. Detailed analysis of the
switching dynamics at high gate voltages shows that the device is driven into
the multiple phase slips regime by high-energy fluctuations arising from the
leakage current.
