I guess if we're having a tunnel, and it's to be bored, then there's not much doubt that a long one would be better. Except for the cost.
So in supporting the short one, are EH simply saying "be realistic, the govt. won't pay any more?" or are they saying there's actual benefits in the short one in preference to the long one?
Seems like the lead heritage body, whose opinion might sway the balance, is doing what the govt. wants rather than acting as a heritage guardian. Or is that unfair?