It's the one channel not marked as 'HD' so I suspect not. The ticker looks a little jarred. It's also not available on the BTTV YouView NOWTV app. .
I watched Ian King Live through the Now TV guide and it has the green tint shown on the logo on Sky News SD and on the apps which are 720p.
However I suspect it's 1080p/25 because it showed way too much detail on Emma Crosby's face and the appalling lighting in the Sky News studio at CNBC which I didn't notice when watching in 720p using the Sky News app.