Of course the problem is that it makes it unsafe for the next electrician whom has to work on that panel. Lucky the sink is plastic.
I provide electrical maintenance for an apartment complex in Indiana. You wouldn't believe it, ALL their electric panels are in a closet behind a water heater. One of them you have to use a stubby screw driver to get the bottom panel cover screws off. All whilst standing on a step stool and laying on your chest on a metal water heater with copper pipes touching your arms. None of them have standing room in front of the panel. Because the water heater is their.
If I had to do much to the panel. I would tell them will have to move it. Lucky most of the calls evolved something other then a breaker or panel problem. This complex is only ten years old.
I have told them in writing. That for safety they need to meet the clearance code for the electric panels.