It's so important that it needs highlighting again here. Keep Cornwall Whole – The Fight Continues! - from the great breselyerkeltic blog is a must read. Please do read the blog post and then act. Equally please vist the Keep Cornwall Whole site to see what you can do.
For what it's worth - I've said it before and I'll say it again - a campaign of PEACEFUL yet spectacular and humoristic direct action should accompany any campaign to protect Cornwall. It would gain attention but not alienate the public. More likely, in making them smile, such a campaign would win the public over.