Illustration by John Sadler www.johnsadlerillustration.com 

• MARTIN Plaut (What would STV do to our democracy? Letters, July 7) pits multi-member constituencies against individual ones.

You don’t have to counterpose them. In the additional member system, AMS, you preserve individual constituency members alongside a top-up arrangement. It is used in Germany, New Zealand and, dare I point out, Scotland, Wales and the Greater London Assembly.

Voters have two votes, one for an individual constituency rep and one for a party on a regional list basis. So you get your MP as now (quite likely someone you didn’t vote for, just as now the experience of most Labour voters in south east England, for example) but also representation for your party if it secures enough regional support.

AMS brings huge democratic gains. Take the case of Scotland. There are 129 Members of the Scottish Parliament: one who represents your local area, constituency reps; and seven who represent the larger area that includes your constituency, known as “regional MSPs”.

Labour currently has 17 per cent of the seats (22 of 129 members) in the Scottish Parliament, rather than under 2 per cent of the MPs from Scotland that it has in Westminster under first-past-the-post, FPTP, with its one of 56 MPs.

In fact in the current Scottish Parliament, Scottish Labour won only two seats in the constituencies where FPTP is used. But it got a further 20 MSPs from topping up, bringing the total to a number roughly proportional to the votes cast for the party.

If the Westminster system operated in the Scottish Parliament Labour would be effectively wiped out, with two out of 73 seats, despite winning 21.6 per cent of the popular vote. That is what FPTP can do.

Conversely the SNP with 47.7 per cent of the vote got 62 seats, just under half the total. Without the top-up arrangement it would have had an absolute majority, winning 62 of the 73 constituencies. That is, it would have had 85 per cent of the seats with only 47.7 per cent of the vote. Is that the democracy Mr Plaut would prefer?

What’s not to like about AMS? You can fiddle at the edges, for example, with the top-up arrangements (I would prefer the German system where there is an equal number of top-up and constituency reps).

And you can change the number of MPs per region, and other things besides, to suit the precise circumstance you are catering for. It is beyond time we moved to something like this at Westminster.

RICHARD KUPER, N6