First past the post suits the left and not the right

Politics is not symmetrical which means that fptp is unhelpful. Because people on the perceived left are more collectivist it is less of a problem for them to be disciplined voters. The left do not so much object to voting for the main party as do those on the right. The motivation for people who want a small state to vote for the mainstream centre-right party is that failure to do so results in something worse. They do not generally identify with the party. However, in contrast those on the left are happy to vote for (and support) their party because doing so is not inconsistent with their beliefs. Fptp is good for the left because party loyalty is more of a contradiction for the right than the left. The fractured nature of the liberal vote means that fptp favours the left.