Mark Pack provides a set of automatically updated campaign buttons for use on Liberal Democrat websites. You can see an example of these buttons in action in the accompanying screenshot.
Back in October 2012 I gave Mark a hand updating the code for the buttons and adding the option of being able to choose different colour schemes. (See examples)
Setting up the buttons on a WordPress website is really pretty simple, just follow the instructions on Mark’s website, but to make it even easier I have created a WordPress plugin that creates a widget you can use to add the campaign buttons to your theme. Using this widget also makes it easier to switch between the different colour schemes.
To use the plugin download the zip file. Unzip it and add the folder to your WordPress plugins directory using FTP. Go to the plugins page in your website’s WordPress admin area and activate it. The widget should now be available to use in your theme’s sidebars on the widget admin page.
Update February 2017: Plugin is now also available on GitHub.