I'm fascinated to see the apparently limitless efforts that both the media and his own party went to in order to brand Corbyn as an extreme and dangerous left winger and undermine his progress. His policies were comparable to, and sometimes to the right of, those of the SDP. The SDP being the right of the Labour party who split in the 1980s and later merged with the Liberals to give today's LibDems. He was more of th…
This article is the exact opposite of what you're claiming. Labour HQ was trying to make him appear less left wing than he is, by refusing to run the more extreme ads that he was demanding.
They chose to "refuse to run the more extreme ads" that were well within the bounds of moderate Labour policy of relatively recent years. With a manifesto that resonated pretty well with voters on most issues as it turned out yet didn't include several of Corbyn's actual well known fringe views such as unliatera disarmament as that went against agreed party policy. The manifesto is what counts.
Thus he's being treated as some dangerous extremist whose views can't even be let out in public during an election campaign. Views that, as put forward in the manifesto, are not actually that extreme. It's miles away from Foot's longest suicide note manifesto for example.