I will concede ground on the fact that he is most likely to be the next PM and therefore has a reason for being there on those grounds, but I am truly cynical that he was visiting in any capacity as Chancellor.
He was there to make him self look good in the publics eye for when he takes over for the remainder of labours rule.
He ought to make the most of it because I truly think that Labour have lost the public over the war and the Conservatives will get in next.