One of my ‘beta’ testers raised the excellent question of why the system uses the same regions as we use for the European elections, rather than, for instance, counties.

The fundamental aim of PR is to provide as many voters as possible with representation. The smaller the number of seats allocated, the less representative the results are. For example, if we allocate 10 seats, then a party will generally require 10% of the vote to win a seat. If we allocate 100 seats, each party needs only 1% of the vote for an MP.

The logical conclusion is to maximise the area over which we allocate the top-up seats. In theory we could do this at a national level, but this has two significant negative impacts. Firstly, it distorts the effect of regional parties such as Plaid Cymru who do very well within Wales, but have no presence outside. Secondly, national level MPs would have no real local connection at all; a common complaint with PR systems.

If we move in the opposite direction and reduce the size of the allocation area to counties instead, we will only be allocating a handful of seats per area, making the minimum percentage a party needs to earn a seat too high. All that would happen is a slight redistribution of seats amongst the big parties, which is no longer desirable in an era when the smaller parties are achieving an ever increasing share of the vote.

Therefore, the regions present themselves as a good balance; they are large enough so that parties need between 1.4% and 4% to win a seat, and small enough so that MPs will still have an area that they are responsible for.

It also means that the Scottish and Welsh (and voters in each region) are able to vote purely for local candidates, knowing that their votes won’t be used to elect someone from the other end of Britain.

Finally, the public are already used to the concept of regional voting through the European elections.