I was going to point out that UK Green party supports a basic income, but now I find that they have dropped it from their 2015 manifesto.
http://www.telegraph.co.uk/news/politics/green-party/1138380...
http://www.telegraph.co.uk/news/politics/green-party/1138380...
The Greens' "basic income" is only a partial one, though; most notably it's set at a level that couldn't possibly replace Housing Benefit, and so doesn't avoid the welfare trap.