South Shields MP Emma Lewell-Buck has warned Metro users that the latest network shut-down will not be the last – with new carriages still two years away.
And - even after the planned upgrade in 2021 - she says she fears that other infrastructure improvements are needed to ensure the rail system endures less disruption through unforeseen closures.
The Labour MP spoke out after trains between Newcastle city centre and Heworth were hit by infrastructure problems at 2.30pm on Thursday.
The powerline malfunction, which forced thousands commuters to take buses to South Shields and Sunderland, took 10 hours to repair.
At around the same time, a broken-down train halted services between South Shields and Chichester.
The delays were the latest to hit a system plagued by technical woes and whose rolling stock is almost 40 years old.
Ms Lewell-Buck, who was vociferous in a campaign that led the government to fund £362m of new rolling stock, said she feared commuters’ nightmare journeys would persist.
She said: “People might have to suffer this until 2021, which is very unfortunate and not good enough.
“Another two years is a long time when you’re trying to get to college or are late getting into work.
“New trains need new tracks and stations, and I’m also going to be looking at that. However, the majority of delays are caused by Metro cars.
“When the system works, it’s brilliant, but until we get new Metro cars, we will get these problems.
“South Shields is at the end of the line, and the impact always seems to be felt greatest in my constituency.”
In 2017, Nexus, which operates the network, secured the multi-million-pound Government grant, which will fund the bulk of the replacement train project.
Eight-four cars are planned to enter service, with the first scheduled for late 2021.
Five companies are on a short list to build the carriages, which will be whittled down to three this summer, with a final decision in the autumn.
A Nexus spokesman said: “Nexus is currently in the process of procuring a new £362m train fleet which will be delivered from the end of 2021.
“We know that our customers want new trains and this will be delivered.
“We are also working with South Tyneside Council to build a £21m new interchange in South Shields opening later this year.”