Most Conservatives will remember New Labour's promise to look at a more proportional voting system in their 1997 manifesto. (conservativehome.blogs.com)
There are a number of proportional voting systems, but in general, they let each voter select a party, the party has an ordered list of candidates, and each party is allocated seats to assign to their candidates in proportion to the number of votes the party received. (politics.stackexchange.com)
In response to these problems, New Zealand has since adopted the mixed - member proportional voting system. (en.wikipedia.org)