The term ‘Proportional  Representation’ (PR) can mean different things to different commentators, and there are several different PR systems. This term applies only to a system that counts the votes cast and translates them into votes in the House of Commons such that there is a direct and (near) proportional link between the votes cast for the various political parties in the General Election and the votes those Parliamentary Parties will ‘control’ in the Parliament. The term ‘near’ is necessary because perfect proportionality cannot be achieved, and is not necessarily desirable. Most people agree that a nascent political party needs to reach a certain level of support before it can expect to be represented in Parliament.

‘First Past the Post’ (FPTP) and ‘Alternative Vote’ (AV) systems are not PR systems. Neither is the Single Transferable Vote (STV) system.
You may argue that STV gives near proportional results but firstly, there is no direct proportional link and secondly, in certain circumstances STV is a far from proportional system. For example it would not have produced a near PR result in the last UK General Election.

Some people think PR systems will produce more representative parliaments, meaning that the Parliament will have a more representative makeup in terms of gender, ethnic origin, social background, disability, age, education, wealth, etc. This is not necessarily so since the prime aim of a PR system is proportionality for political parties in terms of parliamentary votes, not the different strands of our society that go to make up the parliament. It may be a by-product of PR but nothing is guaranteed.

If PR is only about ‘party proportionality’, is this enough? Much as some people deride political parties, our system of democracy depends on them and could not function without them. Defenders of the FPTP status quo argue that our democracy depends on the election of local representatives who come together to form a Parliament. This is ingenuous. Voters may not know much about their local MP but even if they do, in a General Election, they are likely to base their voting decision on party and its manifesto (or prospective Prime Minister) rather than the individual constituency candidate. Remember with FPTP you have one vote to vote for Candidate, Party and Manifesto, and Prime Minister.

PR focuses on producing a result that reflects the fair balance of votes for all the different political parties. For this reason PR (as a generalisation) is a demonstrably a fairer, more democratic system of election than the ‘First Past the Post’ or ‘Alternative Vote’ systems.

If the voter is asked on the ballot paper to vote for a party rather than a candidate, it is possible to say how many votes each party should have in the parliament, based on the votes cast for each party across the whole country.
Let’s call these numbers the ‘Fair Votes’.

Can you have ‘Fair Votes’ in a parliament? It depends on the electoral system.

First Past the Post cannot result in ‘Fair Votes’ except by an unlikely accident.

In order to reflect the way the votes were cast, many ‘proportional voting’ (PR) systems try to match the number of MPs to the number of Fair Votes for each party. In each case compromises have to be made. Some compromises are less satisfactory than others.

This is most clearly seen in List PR systems where MPs are ‘elected’ from a party list in proportions as close to the Fair Vote numbers as possible. The compromise is that the voter has little influence on the election of the individual MPs. The Party determines the order of candidates on the list. There are no constituency MPs.

Other ‘hybrid’ systems use a mix of constituency MPs and top up list MPs. This means two types of MPs and two ways that they may be elected. These systems require new larger constituencies than those in use for the current FPTP system.

DPR Voting overcomes these problems.
DPR Voting bypasses these issues by simply sharing out equally the number of Fair Votes for each party amongst their elected constituency MPs – the members of the parliamentary party. The total number of parliamentary votes each party has is still the Fair Votes total. Each MP has a share of these votes equal to every other member of that parliamentary party. No change to constituencies is required.

An advantage of the system is that all MPs are constituency MPs and can be elected based on the merit of the individual rather than their party label.