The East Coast Main Line recast website currently lists a second hourly Manchester to Newcastle service as an aspiration which can't be met in the December 2025 timetable.
Current times for York to Manchester are 1:17 for Newcastle services and 1:42 via Wakefield, so services would be noticeably slower for passengers to Manchester in general, but more or less the same time for those going to Manchester Piccadilly. The time difference is also half that of London to Crewe via the Trent Valley vs Birmingham.
The main issues I can think of are the rolling stock, Leeds, and places other than Leeds. Looking at RTT, I think the services are run by stock limited to 100 mph; if TPE don't have any other rolling stock they could use, I'd guess that that wouldn't be fast enough for Northallerton to Newcastle without delaying other services.
Getting Newcastle to Leeds to 3 tph is probably a more useful service than hourly services from Huddersfield to Thirsk or Newcastle to Marsden, so I don't think a through service should be kept if / once a second Newcastle – Leeds – Manchester could be restored. A through service also has the risk of making the service too unreliable and too busy for routes like Slaithwaite to Manchester / Leeds or Wakefield (Kirkgate) to York with fewer alternatives.
It wouldn't be an ideal solution, but how feasible would it be to extend the current Manchester to York via Wakefield services to Newcastle? I haven't checked all times and I don't know if the Wakefield services are staying in the same path, but I think the current services would be ahead of any following services in the December 2025 timetable by at least ten minutes going from York to Newcastle.Timetable development is evolutionary and where feedback has not been able to be taken into the final timetable to start in December 2025, specifically two trains per hour between Newcastle and Manchester, the industry is working with Funders (e.g. Department for Transport) to increase further capacity on the ECML in the future to enable such services to operate.
Current times for York to Manchester are 1:17 for Newcastle services and 1:42 via Wakefield, so services would be noticeably slower for passengers to Manchester in general, but more or less the same time for those going to Manchester Piccadilly. The time difference is also half that of London to Crewe via the Trent Valley vs Birmingham.
The main issues I can think of are the rolling stock, Leeds, and places other than Leeds. Looking at RTT, I think the services are run by stock limited to 100 mph; if TPE don't have any other rolling stock they could use, I'd guess that that wouldn't be fast enough for Northallerton to Newcastle without delaying other services.
Getting Newcastle to Leeds to 3 tph is probably a more useful service than hourly services from Huddersfield to Thirsk or Newcastle to Marsden, so I don't think a through service should be kept if / once a second Newcastle – Leeds – Manchester could be restored. A through service also has the risk of making the service too unreliable and too busy for routes like Slaithwaite to Manchester / Leeds or Wakefield (Kirkgate) to York with fewer alternatives.