However the UK parliament(unlike S'pore) has an upper house(House of Lords).
The House of Lords scrutinises Bills that have been approved by the House of Commons (lower house or eqv to our parliament).It regularly reviews and amends Bills from the Commons. While it is unable to prevent Bills passing into law, except in certain limited circumstances, it can
delay Bills and force the Commons to reconsider their decisions. In this capacity,
the Lords acts as a constitutional safeguard that is independent from the electoral process.
In UK,the independence of the judiciary is confirmed through statute, constitutional convention, and weight of opinion. In England and Wales,
judges in superior courts
cannot be arbitrarily dismissed by the executive, instead serving whilst in "good behaviour". Those in lower courts have similar protection from dismissal without due cause. Most
members of tribunals cannot be dismissed by members of the government department of which they form part. This is important in cases of judicial review and other judicial methods of
preventing government abuse of power
.
http://en.wikipedia.org/wiki/Separation_of_powers_in_the_United_Kingdom