IMHO, these are not the only reasons you should be worried about. Pushing more microsoft proprietary software into local government means more your tax dollars will go to usa (not to usa government, probably, since there are so many tax schemes available).
On the other hand integrating open source software in organizations usually done with help of local companies, meaning your tax dollars spend on work your neighbor do. Since in this case you are not paying for "product", you are paying for integration of open source software. (as a bonus, it often also saves bucks on software products, even if you pay more for integration/training).
ps: not saying that during process of integration of open source software often changes/bug reports/feedback contributed back to open source community, which benefits all people...
We already buy a load of stuff for government from the USA.
Regardless of what software they choose they will probably outsource the IT management to a US company anyway.
The British don't really make OS software anymore , so trying to buy british doesn't really make sense here.
I'm not so bothered about what the government chooses to buy, I am more worried about the government forcing it's citizens to buy specific software.
With open source software (which mostly uses open standards) you do not "buy" anything. Instead you adapt particular open source product (be it training, integration with other company's software, etc).
To do training most likely you need local training company. To do integration, I agree after certain project size it might be possible to outsource it to another country. But even then - you most likely end up outsourcing to India, not to USA. Which again - lower total price.
Most Government IT in the UK is outsourced to the British arms of consulting companies like EDS or Accenture.
I suppose you are still employing British people but you would be even with an MS solution, the only difference is the licensing costs which may or may not be an issue.
I'm assuming MS licenses for workstations aren't that much of an issue otherwise FTSE 100 companies would not predominantly use it.
On the other hand integrating open source software in organizations usually done with help of local companies, meaning your tax dollars spend on work your neighbor do. Since in this case you are not paying for "product", you are paying for integration of open source software. (as a bonus, it often also saves bucks on software products, even if you pay more for integration/training).
ps: not saying that during process of integration of open source software often changes/bug reports/feedback contributed back to open source community, which benefits all people...