A quick look at the Green Party website and other digital channels. I'm only approaching this from what I can find after a quick look around. I do not know what their offline marketing is pushing or how most people are using/finding Green Party material. Other posts looked at The Lib Dems, the party HTML newsletters, the Conservatives and Labour.
Website

The more observant amoungst you will have noticed that THEIR WEBSITE IS GREEEEEN! Yikes. The only pictures on the first page (besides icons) are Photoshopped headshots. The main call-to-actions are for information on five of their main policies (there's not 'read more' so maybe they only have five?) and a link to their manifesto. Further down the page there are links to join, donate, find your local Green party member, sign up for updates, Twitter, Facebook and the members club. All pretty standard stuff. Some of the icons aren't even Green!

One thing I do like is a little note before signing up—they tell you they'll email every two weeks, possibly more during election time. That's a nice addition to the page. Makes up for the annoying/hard to find 'click here to sign up' link you have to hunt for.

Few complaints as I click around... They don't add images into the content, making it all look a little dry. There are images at the top left, but these peter out after about 1000px down.
The other thing I don't particularly like is their messing with some pretty standard internet conventions—Links being underlined. That chosen a charcoal colour for links with the text bold. Their titles and subheadings are all the same size, but are also bold... I found myself moving my mouse around trying to figure out which were the links. Maybe that's a problem, maybe it's not, but there's a chance that people will miss these things.
Another niggle is the top heading picture. Couldn't we get a few different ones as we move through the site?

Their donate page has some nice 'this is what we can get for 10 quid' type waffle. If it works for charities, it'll work for the Green Party.
After a few minutes on the site I realised they seem to have hundreds of not-so-micro-microsites. Some are set up as sub domain e.g. peterborough.greenparty.org.uk whereas others seem to be on any random domain (but clearly use the same site setup as the main website) e.g. www.brightonhovegreens.org
Enough on the website,,, it's alright, but could probably be better.
Facebook (#FAIL)
Ooh, that looks like the Facebook icon! I think it'll click it and become a fan!

Oh dear. 404 link from your main page. They set up some kind of redirect page (for counting clicks?) to their Facebook profile but that's obviously not working. Would people bother going to Facebook to find them if they saw that? Probably not. So neither will I. A branded/more useful error page wouldn't be a bad thing either. Also, the 'back to homepage' link just links to the same error page. Help! I'm stuck!
Twitter

Phew, that link worked. They follow 3000 people and have 9000 followers. That's pretty good going. They send out a mixture of stuff, from retweets of people patting them on the back, to links to website content and articles. They are listed by nearly 600 people. They also have a list for Green party twitterers, and background that can only be read on widescreen monitors.
YouTube

700 subscribers to a good mix of videos. They post party broadcasts, interviews, a few fireside chats, few mini history lessons... Not bad. Not half as many blokes in ties as the other parties. They also don't quite have the same cult of personality (on their YouTube channel) that the other parties have either.
Young Greens

They have a community website for Young Greens that has articles aimed at ... Young Greens. A few images dotted around and this might even get some people revisiting.
Online Magazine

They also have Green World, an online magazine currently in its 66th edition. Word of warning for anyone without 20-20 vision, the font-size is tiny on article pages. All past editions are available to download as PDF without having to register. Seems like a good place to quickly ask for peoples email address, but maybe that's just me.
Agency Microsite
Linked to from some of their profiles/pages is www.onlygreen.org.uk that contains some professionally produced videos with easy options for sharing. There's also a nice option to merge one or two of the videos and email onto a friend.
Those seem to be the main sites the Green Party are using for online exposure. I understand the party probably doesn't have the budget the others do, so I guess they made a pretty good effort. No major complaints, just a bit rough around the edges. Mind you, I haven't been bowled over by any of them. I don't think American graphic designers are frantically discussing the typeface choice on the Conservatives website or the colour scheme used by Labour, or the ground-breaking design for the Lib Dems. Remember the Obama campaign?! Maybe it'll all get a bit slicker closer to election. Here's hoping.
About the Author
I'm Paul Ashton. I'm part Web Developer, part Web Designer, part Digital Marketing type person. I can often be found waffling on Twitter: @paulashton1979. Feel free to send me a message, leave a comment below, or get in touch if you think I can help you in any way.