HULL City Council is calling for reassurances from Network Rail the region will not be "cut off" by lengthy work to repair damage caused by a landslip.
Three weeks on from the landslip in Hatfield, rail services are still disrupted, with repair work possibly extending into summer.
Now, Councillor Martin Mancey, the authority's portfolio holder for transport, believes planned work to replace a swingbridge in Selby should be put on hold as a precaution in case repairs take longer than expected.
But Network Rail, the organisation responsible for maintaining the railway, says work to replace the bridge – due to begin in July – will continue as planned.
If there is a crossover, commuters face delays and bus replacements.
Cllr Mancey said: "The council is seeking assurances from Network Rail that they will reschedule planned work on the Selby swingbridge if the issues caused by the landslide at Hatfield on the Hull to Doncaster line are not resolved by then.
"Unless Network Rail resolves the significant problems on the route, they need to delay any work at Selby, otherwise Hull and its economy of more than 400,000 people will be effectively cut off from the UK's strategic rail network, which is unacceptable."
Emergency engineering works are currently being carried out after the landslip, which happened on February 11.
Network Rail says, in recent days, it has become apparent the damage to the railway is a lot worse than it originally thought and repairs will be complex.
However, there are currently no plans by Network Rail to delay work on the Selby swingbridge, set to take place from July 28 to September 9.
A Network Rail spokesman said: "Teams are currently planning that this will go ahead as scheduled.
"In the event that the work at Hatfield is still under way, this will limit the diversionary routes available to passenger services.
"Work is being carried out with the train operators to identify alternative arrangements during this time.
"Detailed information will be published as soon as it is confirmed."
Usually, First Hull Trains travel on a route via Selby to Doncaster, stopping at Howden.
However, the firm will be unable to use this route when the engineering work is taking place.
First Hull Train's usual contingency route, via Hatfield and Goole, is unusable due to the landslip.
A First Hull Trains spokesman said: "A few weeks ago, we managed to overcome the operational challenge by using another route.
"If the work at Selby goes ahead, we may need to use this route again or we will look for further alternatives.
"Our objective will be to keep our passengers on the move, without having to transfer to road transport, wherever we can.
"We are talking to all relevant parties in connection with the work in Selby and its potential impact on our services – especially in view of the recent landslip on our alternative route."
