How does this compare to the political preferences of humans?

The UK Conservative Party and the US Republican Party are quite right wing by international standards, wouldn’t it be fair to expect that to show up here if the LLMs were neutral?

This is a very good point. Would be lovely to see a) representative survey data on this for countries, where available b) the aggregate results from the websites that do offer this to humans (like political compass.org, which is one of the tests they do).