Its results at the 2017 General Election were as follows:
(I've left out people's names for brevity, and I just lifted these numbers from the BBC's web site. I've given the percentages a cursory check.) This, as a pie chart, looks as follows:
An immediate observation is that the winner of the election received only 60% of the vote, so there is a whopping 40% of people who voted who are entitled to feel unrepresented. Whilst I'm sure the winning candidate would represent in the sense of helping the constituent with a particular problem, that person would nevertheless go into the debating chamber, and probably vote contrary to what 40% of his/her electorate might think.
My view would see the top three candidates elected. Just looking at Salisbury, you can say that the number goes up from 60% to 95%. OK, still not everybody is represented, but it's a lot closer than before. As a broad Green Party supporter myself, though, I can say that many of my views are the same as those held by other left-of-centre parties, at least approximately. I mean, I only agree with the Greens approximately, in any case. So I could live with this fault. I mean, ultimately you have a trade-off - the more MPs you have per constituency, the more people's views are represented, but the bigger your parliament becomes. Some would say that at 650, it is pretty unwieldy already! Bear in mind that even now, a far larger country, such as the USA, has a smaller lower chamber than the UK.
So, I have my three MPs. How is their vote split once they get to the House of Commons? Well, I think you need to do a little bit of maths at this point. First, you say that these three candidates are elected, period. You then discount all the failed candidates and re-calculate the proportions. So you have the following:
|Party||Vote||Percent of vote from the total electorate||Percent of vote, compared to other "top three" candidates|
Note I've added another column, which just compares the "top three" to each other. Lo and behold, (61.23 + 26.94 + 11.83) equals 100. And this last column becomes the proportion of the vote assigned to each of the winning candidates - the Tory guy has a vote of 61.23%, or 0.6123, the Labour guy has a vote of 0.2694, and the LibDem a vote of 0.1183. Again I'll put that table as a pie chart, just because some people interpret graphics better than text.
Note finally that the only thing which would need to know these numbers would be the voting system used in parliament, although of course they should also be released to the public, for transparency's sake. But your MP would basically have something which says, "I am X", and parliament's system would say, "X has 0.6123 (say) votes". The MP would not need to remember the number.