Radical plans to ease overcrowding on the regions most congested rail routes could be delayed for up to two years, ITV News Meridian can reveal.
Big rail projects could also be hit. But the disappointment for passengers in the Thames Valley and the south will be having to put up with overcrowding for longer than expected on key routes from Paddington to Reading, Oxford and Newbury. Also hit could be the line from Reading to Basingstoke and south coast Great Western services from Portsmouth to Cardiff.
A formal announcement will be made within weeks as Network Rail decide how it will deal with project overruns and a funding crisis.
?The problem is caused by a massive increase in costs and delays to electrify the Great Western line. The price was £874 million in 2013. But that has now risen to £2.8 billion and is delayed. Unexpected problems and a lack of engineers lead a long list of issues it has faced.
A new £500 million link from Reading to Heathrow, aimed at cutting jams on the M4, may also be delayed as resources are diverted to the over budget electrification project.
There are also fears a £300 million scheme called East West Rail to link Oxford and Aylesbury with Bedford and Milton Keynes could be put on hold for up to seven years.
The problems mean 58 new electric trains for the Thames Valley will not be introduced as planned from next spring. They're meant to increase capacity by 25 per cent and speed up journeys. The diesel trains they are replacing where then meant to move to other parts of the network to increase capacity along the south coast, Bristol and Exeter, so there is a major knock on.
Great Western Railway will be unable to run the electric trains because the overhead wires and gantries to hold them up are far from being installed.
There are also questions over the new high speed Hitachi services costing £5.7 billion pounds from 2017. Some of the trains run on diesel and electricity but others may have to have diesel motors added to stop them sitting in the sidings. It is unclear when they will run.
Network Rail and the Government, who own it, will reveal how it plans to proceed in the next few weeks but those inside the project have told ITV News there will be major delays, possibly up to two years.
It is thought they will focus on the key mainline route from Paddington to Bristol and delay sections due to be upgraded from Reading to Newbury and Basingstoke and Didcot to Oxford.
The company say a review is still underway but insist work is taking place and when it is complete passengers will have a world class railway with more and faster services that will revolutionise rail travel.
Great Western Railway finds itself in the middle of the mess having promised passengers improvements it will not be able to deliver because of no fault of its own.
They have already converted poorly used first class carriages to standard class and added every extra carriage it can. The company say they are investing more than half a billion pounds of its own money on fleets of new trans, Wi-Fi, station upgrades and other passengers improvements. Its sleeper service is also being given a radical upgrade.
It like its passengers, who face the most crowded trains in the country, await the announcement from Network Rail to find out just how long the delays will be and how it will be sorted out.