See what they come up with
1.8 million people may sound a lot but the UK population is an estimated 60 million, assuming half of these can drive that means only 6% of motorists objected to the scheme (and therefore 94% did not object but aren't kicking up a huge stink about it).
I'll be the first to admit I'm a sit on the fence kind of person and I'm happy to wait and see what they come up with before objecting. I can't imagine the different parties will all come up with the same solution and so a general election will soon sort it if they get it wrong (anybody remember the poll tax?).
I probably do 3000 miles a year which makes my road tax extremely expensive per mile compared to somebody who pays the same but does 10x that amount. Assuming they propose to take the same overall revenue that they would take from road tax then I'll be all up for it, it means the people that drive a lot will pay more than those that drive very few miles, that sounds completely fair to me. Compared to the tax on fuel it's not really a significant amount to those that do a lot of miles anyway.
It will take more than a single scaremongering email with no proof of factual information to make me sign a petition...