Treaty of Lisbon (No. 5)

I think that the Foreign Secretary will find that the clear answer to which he just referred is that the Government did not want the two posts to merge. Apart from the change of name, is there any difference in substance between what was envisaged in the original constitution—a Union Minister for foreign affairs—and the high representative envisaged in the Lisbon treaty? What is the substantive difference, apart from the name change?