The Green Party also exists in the Czech Republic. It has 950 members. In the years 2006-2010, the party entered the Parliament and the government. Their policies have been so disastrous that they currently regularly get about 1% of the vote in our elections. This keeps them away from parliament.
It's a bunch of friends who get together or hang out at various events due to lack of public interest. I can't imagine what would happen if they got back into government by some mistake.