run by charity mySociety
Write to your politicians for free using the Write To Them website. The site makes it easy to find out the relevant person to contact, draft an email on the site and then it will send from your email address.
Online petitions are a great way to gather momentum behind your cause, but it can be tricky to know how to make them successful. There are a number of websites that can host online petitions, but this advice is campaign site 38 Degrees.
A useful map created by Starboard Blue so politicians, regulators and activists can see current plastic bans and taxes globally, all in one place. If you like matrices more than maps, you can find the same data displayed differently here.