This would have run during children's programmes on ITV (the UK's only commercial channel at the time) to coincide with the first issue hitting newsagents shelves in February '77.
The practice of launching a new comic with a TV campaign was phased-out in the following decade as sliding sales no longer justified a substantial marketing budget for new titles. That left publishers to cannibalise their existing readerships by relying on in-house advertising.
New toy-based launches like THE TRANSFORMERS and ACTION FORCE did benefit from TV plugging (although the latter weekly still only survived a year) but those spots were bankrolled by Hasbro.
If you're wondering where Judge Dredd is, he didn't appear until the following Prog. and wasn't intended to be the weekly's star turn. How times have changed.