I think the solution to this problem is to have a hybrid voting system. Half of MPs elected in constituencies as now, half by a regional "open list" system where we vote for a regional candidate.
You walk into the polling station and you are ticked off the address book by the officials. You are given your constituency ballot paper with it's official stamp and you are directed into the private polling booth (as is the case now).
Now for the differences. You get two votes, one for your constituency MP and one for a new regional MP.
You place an X by your chosen constituency candidate and fold the paper.
Then you choose ONE of the regional ballot papers stacked in the polling booth for your regional vote.
They are all colour coded on the printed side with party colours or white for independent candidates.
You choose which ballot paper depending on which party or independent you want to vote for then place an X next to the candidate of your choice from that party or independent candidates.
You fold your regional ballot paper which is neutral black on the other side. Show your official stamp on the outside of your constituency ballot paper to the officials, receive your stamp for the outside of the regional ballot paper and you post both your folded ballot papers into the appropriate ballot boxes.
You will be voting for a constituency MP as you do now and a regional MP under an "open list" system.
The constituency MP will be elected as they are now, on a "first-past-the-post" basis in constituencies about twice the size. So 150,000 electors on average instead of 75,000 now. So for example, Brighton could be one constituency instead of being split into Pavilion and Kemptown.
As well as 15 constituency MPs in a region, there would be an equal number of regional MPs. So, there would be 15 regional MPs covering around 2.25m electors. About the size of Sussex and Kent combined. This would total nationally to 325 constituency MPs and 325 regional MPs. A total of 650 MPs, as we have now.
Each party could field up to 15 regional candidates for you to choose from (or you could choose an independent candidate). You vote for one candidate out of the list and the number of votes for each candidate determines the order of each party's regional allocation or the order of independent candidates.
These regional MPs would be shared out proportionately to each party or group of independents according to their total share of the region's votes.
So if for example Green candidates got 20% of the total regional and constituency vote combined in that region, they would get a total of at least 3 MPs. If they got less than 3 constituency MPs, their regional candidates with the most votes would make up the total to the 3 MPs required.
This would allow for a reasonably proportionate share of seats to votes for each party or independent. But crucially EVERY elected candidate would have been chosen by the voters.
For example, in Sussex and Kent under our present system, the Tories got 45% of the vote but 92% of the seats.
Under the new system, the Tories would still get 92% of the constituency seats on 45% of the vote, but that would only be 46% of the total seats. Because they would be unlikely to get many (if any) of the half of seats allocated regionally, as these would be allocated in proportion to parties' total voteshare.
The effective threshold would be about 6.5% for a party or independent to get one regional MP (100% divided by 15).
Parties might very likely decide not to put up as many as 15 candidates, though there is no disincentive to do this. It would make sense for a party to put up a wide range of candidates from all wings of the party to garner as many votes as possible. And this gives a voter a chance to influence party policy directly by voting not just for that party but the candidate they like from that party.
In our current system there is huge disproportionality between regions. Tories have very few constituency MPs in urban areas, the North, Scotland and Wales compared to their voteshare. They would likely win some regional MPs there to compensate them for this. Likewise Labour would win regional seats in rural and Southern England, also now in Scotland to compensate for the fact nearly all constituency MPs are Tory in the South and rural areas, and SNP in Scotland.
The smaller parties that are not so geographically concentrated, would do very well out of regional seats. As long as they can get over 6.5% of the vote in that region they can win a seat.
The result under our present system in the 2015 general election was, (rounded to 1 significant figure).
CON 37% vote, 51% seats
LAB 31% vote, 36% seats
SNP 5% vote, 9% seats
LDEM 7% vote, 1% seats
UKIP 12% vote, 0.2% of seats
GRN 4% vote, 0.2% seats
OTH 4% vote, 3% seats
As you can see, a fairly random and totally disproportionate and unfair result in terms of seats to votes.
With my suggestion of a hybrid "open list" system, the results on the same voteshares would look something like this. (note: I'd expect very different voteshares as there would be less need for tactical or protest votes).
CON 37% vote, 41% seats
LAB 31% vote, 34% seats
UKIP 12% vote, 10% seats
LDEM 7% vote, 4% seats
SNP 5% vote, 6% seats
GRN 4% vote, 2% seats
OTH 4% vote, 3% seats
Yes, I know this would very likely lead to a Tory/Ukip coalition government. But, that folks is democracy.
If over 49% voted for these parties, it is not unreasonable that they get around 50% of seats and into power. But I do believe that those UKIP voters that are on the left economically would quickly abandon Ukip once they saw them enacting their rightwing policies in a Tory led government.
Any new system takes time to bed in. For this reason, I think the first 3 general elections under this new system should be every 2 years before reverting to every 4 years. This should mean voters can get used to what they are voting for and any parties that are "conning" them (UKIP?) would be quickly removed.
As you can see, smaller parties all get seats much more in line with their voteshare. They get a few percent less seats if they fall below the 6.5% threshold in some regions, which means they win no regional MPs in that area.
Most of the Others total are Northern Ireland votes and seats and therefore regionally concentrated, so not falling below the threshold.
I hope you can clearly see how much fairer and democratic this system is. All the MPs are still voted for directly. Voters can feel more free to vote for candidates from parties they really support knowing their vote will count.
This system is similar to the hybrid systems used to elect the Scottish parliament and Welsh assembly, and also the German and New Zealand parliaments.
The difference is the "top up" regional candidates are "open list" and chosen by the voters and not by the party providing a "closed list" of ordered candidates elected due to party preferences.
This I feel deals with the criticism that regional MPs can "hide behind their party vote" and are not directly accountable. If a regional MP is unpopular, they can be directly punished by the voters. Voters can also do this without punishing the party they are from (if they so wish). Candidates will be less beholden to their party than now where 75% of seats are safe.
We will still have some safe seats in the constituency half of seats. And in these seats MPs will still be elected with "most" votes even if they get less than 50% of the vote. I would have introduced an AV element here but because this was rejected in a referendum and because I wanted the system to be simple I went for the well known X on the ballot.
So to sum up. I hope you can see that this system is both simple and fair. I've gone into detail describing the voting process, because I want to demonstrate its simplicity.
You put an X by your choice for constituency MP and an X for your choice for regional MP from your chosen party or independent candidates list.
The counting process is also easy. Most votes for a candidate in a constituency elects the constituency MP.
The regional MPs are elected proportionately. So if 30% of votes for candidates are from one party. 30% of their candidates in order of most votes are elected.
Other changes I'd like to see are the introduction of a small expenses allowance for turning out (say £20) that recognises the costs involved in voting (both in terms of time and financial).
I would introduce photo ID at polling stations and go back to severely limiting postal ballots to safeguard against fraud.
I would introduce a "none of the above" on the ballot paper. If 50% voted for this option in the constituency ballot, then a person would be drawn at random from the local electoral register to become MP. In the regional ballot a proportionate amount of "jury" MPs to the "none of the above" vote would be chosen.