But it hasn't been funded by road tax. It has been funded privately,
and ultimately by the people who use it. What is wrong with the user
pays principle?

That's fine. However, it doesn't change the fact that the government should
still build a publicly-funded alternative to the M6 - we shouldn't be in the
situation where congestion is so bad that we have to use a private pay-extra
option. It's like giving up on the NHS and telling everyone to get private
health care.

And if that's the route they want to take, then they can damn well abolish
road tax.