they don't have a real party system. they have a first-past-the-post electoral system without fully entrenched major parties. in every election, it becomes the task to become perceived as the likely winner closest to some 50%-ish group in your constituency, and so the object of strategic voting. 1/

unlike under true proportional representation, where you can represent your constituents and no one else, the British system leaves every party and aspiring MP with a strong incentive to avoid alienating litmus-test voters. /fin