The UK parliamentary system makes alliances necessary and difficult for any particular party to seize total control of power. Hence, the work that civil servants perform is unlikely to change between Prime Ministers. In America, well, Jeff Sessions is about to be the Attorney General.

> The UK parliamentary system makes alliances necessary and difficult for any particular party to seize total control of power.

The Parliamentary system means that there is no separation of powers, so "total control of power" just means a parliamentary majority, and most governments have been one-party majority governments (there have been a few coalition governments, such as the LibDem-Tory coalition that Cameron started with, but they are the exception, not the rule.)

Now, if the UK had proportional representation, even with a parliamentary system, that might make one party acheiving total control more difficult than in the US, and enough parliamentary systems are also PR that people sometimes conflate the effects of the two features.

I was taught in high school, that its basically the same here. Though with every election, the incoming politicians make a big deal of replacing various department heads. Its the main reason that government jobs are intended to be unioned and tenured, ie, to protect them from political whimsy. But expect that to come under fire in the next 6 months, unfortunately.

It’s less about unions and more about classifications of employees. Most federal employees are either “career” or “political” positions. Political positions are typically replaced by each new administration, while career employees stay, regardless of union status.

*I’m a federal employee.