Under the UK’s Parliamentary system if an MP dies or steps down during a Parliamentary term a new election in his/her constituency takes place to fill the gap – no ‘appointing’ of new MPs as happens in countries with a party list system.

This of course compels the political parties to stay on their toes to fight such battles as and when they happen, in what often turns out to be a local mini-referendum on the Government’s record.

The outcome is not representative of what might happen at a general election. All opposition parties can pile in forcefully to this one constituency to attack the government, whereas in a general election all efforts/resources are spread across the country.

Still, it makes for livelier politics.

And in the right circumstances the results can be dramatic.