An interesting difference between arious systems is, BTW, the situation of prosecutors. In the US, the Judiciary is independent, while prosecutors are under the government - under the Attorney General who functions as a minister. I don't know the British system precisely, but it is something not significantly different. English doesn't even have a parallel for "judiciary" for prosecutors - but in some other countries, they are nearly as independent as the judiciary. *Lunatic*, n. One whose delusions are out of fashion.
[As a minor point the English Crown Office is part of the High Court office and is the place you go to issue an application for Judicial Review. As ever the English and Scottish legal systems are quite distinct and only come together at the level of the House of Lords - its judicial role soon to be transferred to a Supreme Court, its creation being a sign of the growth in separation of powers ideas in the UK).
In British practise the law officers and prosecution authorities are a semi-detached part of the executive, so political considerations should not affect prosecution decisions.
The first Labour government in 1924 fell, at least in form, when its Attorney General was accused of letting political considerations affect the decision not to prosecute a Communist editor and the Conservatives supported a Liberal amendment calling for an enquiry (which was treated as a motion of confidence).
