Labor is under 10% of the cost of an electric car.
It generally includes the labor for sub-assemblies, but not for components. Components are sourced globally, so manufacturers in different countries should not be paying substantially different prices for components. Certainly sometimes they do, but that's generally a tariff issue, not a labor issue.
Not an expert, this is just based on most of an hour of random Googling.
A high school teacher once told me that the most expensive part of a car is healthcare and pension costs. Road and Track reported on this a little while ago, no idea what the situation is today.
https://www.roadandtrack.com/car-culture/a9590/pension-costs...