The UK is relativly free of Gerrymandering.
pedant alert
This is as gerrymandering is a term that originated from Gerry Mander, a Chicago politician of the late 60's/early 70's. It is the pratice of redrawing boundaries to make seat uncompetitive.

The electoral bias in the UK dates to long before this, and is much more simple. Urban, mainly labour areas genrally have seats with less voters in than rural and suburban seats that tend to be Tory/Lib dem. Small steps have been taken by the Electoral Commission to change this, such as the reduction of number of Scottish seats, but there is a long way to go.

Bunnahabhain.