Rail bosses have come under fire amid growing concerns that planned work to improve the railway line between Blackpool and Preston could be delayed.
Questions have been raised over the electrification of the route after Network Rail confirmed the project is under review.
The company, which has come under mounting pressure in recent days, said it is “committed” to carrying out the work but gave no indication of when it will begin.
Bosses had previously announced the project was being pushed back to early 2017 – but rail users have now voiced fears this could signal further delays.
Blackpool South MP Gordon Marsden, Labour’s shadow transport minister, said: there are “enormous concerns” surrounding the project.
He added: “Coming on the back of the fact this project has already been postponed once by a year, these continuing stories are very worrying.
Why can’t Network Rail come clean and say whether they are going to delay or not?Stephen Brookes
“I will be continuing to press for a concrete answer as quickly as we can got one.
“It is not helpful either for rail staff or indeed for the town and it’s about time we had some specifics both out of Network Rail and our of Government ministers.”
Last year, rail bosses announced the electrification work would not be complete until 2017, rather than 2016 as previously stated.
Network Rail said a decision to push the work back further “will not be taken lightly”.
Rail campaigner Stephen Brookes said: “Indecision is unhelpful – why can’t Network Rail come clean and say whether they are going to delay or not?
“There is an issue here that needs resolving one way or another.”
Blackpool North and Cleveleys MP Paul Maynard said he had received assurances there are no problems affecting the project.
He said: “I realise there have been concerns over the electrification process in the North.
“But I am glad that the Department for Transport has confirmed to me that the Blackpool to Preston stretch has not been paused and is continuing as planned.
“Of course in any engineering project contractors have to deal with problems as and when they find them, but I know from Network Rail that there are no major problems impeding this electrification.”
A spokesman for Network Rail said: “Electrification is a priority scheme and we are working to deliver it at the earliest opportunity.
“We continue to progress our commitment to invest in the line between Preston and Blackpool North.
“The improvements are part of Network Rail’s £1bn-plus investment in the north which will help to provide passengers with a faster, more reliable and efficient railway.
“We are currently undertaking a ‘deliverability’ review of all our enhancement programmes.”
Network Rail said the review could cover all aspects of how the projects can be delivered in order to keep disruption for passengers to a minimum.
The spokesman added: “Any decision to reschedule work will not be taken lightly and we will continue to liaise with the key stakeholders in Blackpool throughout this process.”
The first phase of Network Rail’s North West electrification scheme was completed in 2013, between Manchester and Newton-le-Willows.
The company says the work will improve travel across the North West by making journeys “faster, quieter and more reliable”.
But Mr Marsden said overspends on other projects that have led to delays in other parts of the country have given passengers on the Fylde coast good cause for concern.
He added:“This comes on the back of the Government having to admit that there have been major flaws and over-reach in Network Rail’s projects and other parts of the North West have already suffered.”
Network Rail said it was misleading to link the current review of its enhancement work to a previous announcement that electrification of its Transpennine route, east of Manchester, had been paused.