(please not another thread about the service from Bletchley to Euston...)
Going to jump in here - this is why splitting the CLC is a fundamentally good idea. Capacity at Lime St and Piccadilly is severely constrained and isn't going to be eased without serious investment. Meanwhile Warrington retains its fast trains to Manchester and Liverpool and the intermediate stations get a much improved service. The only real opposition here is coming from anti-light rail types who refuse to accept that light rail is more appropriate in urban areas than heavy rail.
Agreed.
This seems to be about the fact that everyone wants a fast service to the nearest big city without the inconvenience of stopping at several intermediate places... whilst Liverpool passengers want a fast train to Manchester without the hassle of stopping at smaller intermediate places like Widnes/ Warrington, Warrington passengers will want a fast train to Manchester without the hassle of stopping at smaller intermediate places like Irlam...
...but there's not enough capacity on a two track railway to accommodate a half hourly semi-fast as well as giving all of the local stations a decent enough service - hence places like Urmston and Irlam getting a half hourly Manchester service plus one "fast" train per hour (and some other intermediate stations only getting an hourly service, some stations getting worse than that).
The fact that there was no scope in the timetable to accommodate the new Warrington West stop without making equivalent cuts at Sankey shows how tight the timetable is, with the stoppers leaving Lime Street a couple of minutes after the eastbound "fast" and then trying to get to Oxford Road a couple of minutes ahead of the subsequent eastbound "fast" (and vice versa in the other direction).
People in Greater Manchester can't have an appropriate service at their local station because of the apparent need for a fast service from Liverpool to Nottingham - I can see why councillors/ MPs/ Andy Burnham/ TfGM (etc) are frustrated and would rather their constituents had a more suitable frequency - the needs of their constituents can't be served because a combination of two fast and two slow services per hour mean there's no space.
Electrification would improve things, given acceleration, but it's still going to be a horribly tight timetable with precious little scope to improve frequencies for intermediate stations.
However, chopping the line in two would permit places both sides of Warrington to have a suitable frequencies.
Merseyrail have already given up on the "every service has to stop at every station" idea, with some Chester services omitting some intermediate stations, so it's not inconceivable that they could extend the Kirkby/Ormskirk service beyond Liverpool Central to Warrington Central, semi fast from Liverpool Central to Hunts Cross (maybe just stopping at Liverpool South Parkway?).
There is the problem of what to do with Mossley Hill and West Allerton though - dumping those stops on the longer distance Birmingham services probably wouldn't be popular - but maybe there'd be scope to use two of the four freed up Lime Street paths for a half hourly Runcorn stopper (since Runcorn always feels to me like it has a pretty poor frequency)?
That would allow five trams per hour east of Warrington (with a half hourly service from Bank Quay to central Manchester, the existing Chester service, takes around half an hour to get into central Manchester), which would be a big improvement for many local stations.
Plus, with one half of the CLC route freed up from having to match up with the other half of the route, you could see about extending the Metrolink service beyond Warrington Central to serve Bank Quay, improving links - trams can be much more flexible than heavy rail when it comes to such things - look at how Metrolink serves central Oldham/ Rochdale much better than heavy rail ever managed to.
IMHO, Warrington passengers would get a better service in each direction than they currently have, plus their services would penetrate Manchester City Centre and Liverpool City Centre better than the current situation. The real "losers" would be people in places like Widnes who lost their Manchester service and people in places like Urmston who lost their Liverpool service. But I think that the winners would outweigh the losers (and I say this as someone living in Sheffield who'd lose a direct service to Warrington/ Liverpool if this were to happen - but the number of people doing that kind of journey are insignificant compared to passengers doing simple everyday trips like Widnes to Liverpool.