to sign up as Labour supporters, and pay £3 to elect Jeremy Corbyn as leader of the Labour party?
www.theguardian.com/politics/2015/jun/16/jeremy-corbyn-labour-leadership-conservatives-twitter
Yes, you're giving £3 to Labour, which requires some tooth gritting, but the value of an anti-Labour government in 2020 will be incalculable. The £3 would be worth it in comedy value alone.