Well for that, it would need to be a Northern service, who would want extra subsidy to run it, especially if it stopped at extra stations (eg Hartford, NLW). DfT must have set their face against that in the franchise spec, and Northern currently have enough on their plate delivering what they already signed up to. In a world of surplus EMUs though, it would make some sense. It also falls down the crack of local authorities, passing through several different jurisdictions, some without much enthusiasm for rail. Though it all sits under TfN.