There is a very real likelihood that Farage will win the next election Partly because of this countries outdated, first past the post election system.
Under PR(Proportional Representation) parties will usually get the same percentage of seats as their percentage of the vote.
With the electorate split 3 or 4 ways and a lot of people too disillusioned to vote, he could become PM with as little as 20% or 25% of the vote under first past the post.
Under PR Reform would get 20/25% of the vote and therefore get 20/25% of the seats.
If the Tories and Labour support a referendum on PR it will likely be passed as the other smaller parties will support it.
It may mean that the Tories and Labour need to form a coalition after the next election and while this may be hard to swallow, it would be for the greater good to stop the far right getting into power.
The Tories and Labour are both fairly centrist parties anyway so it makes more sense than the Tories and Reform getting into bed together.