That is: some in Alberta, like Ezra Levant, see the Northern Gateway Project as a means of getting tar-sands oil to other markets should the Obama administration impose clean-up measures, like a carbon tax, upon it. Make us live up, and we will send our oil overland to Kitimat and sell it to the Chinese Communists, is the message.
Except that Iggy's move would effectively kill the Gateway Project; so in effect the LPoC position is that the oil-sands must be developed but must not be allowed to escape (literally) their environmental responsibilities.
And while the measure may not play that well in Alberta, its B.C land through which the pipe-line must run, and B.C. waters that a spill would pollute. So it isn't really up to them, is it?