The future of Portishead’s railway reopening is in jeopardy, after it was revealed the project may not open until 2021 as costs have spiralled to more than £100million more than its original budget.

The first phase of the MetroWest project - which is being partially funded by North Somerset Council – would see trains run half-hourly between Portishead and Bristol with the existing railway station at Pill reopened. The project would also include improvements to the Severn Beach branch line service and upgrading stations and services between Bristol Temple Meads and Bath.

It was initially expected to cost £58million when it was first announced, but the Times reported in January the cost was likely to be ‘considerably more’. The total cost of implementing phase one is now believed to be between £145-175million and has been deemed unaffordable by the team implementing it.

At a press briefing in Bristol yesterday (Wednesday), representatives from North Somerset and MetroWest announced the project’s fate would be sealed at the next meeting of the West of England Joint Transport Board on March 17.

MetroWest and the council are now urging the board to approve splitting the project into three stages – the second of which (stage B) would see trains run to Portishead once an hour in 2021 – in an attempt to reduce costs. The first stage (A) would see improvements made to connections between Bristol and Bath and the Severn Beach branch line, while the third stage (C) would eventually see trains run to Portishead every half an hour as originally promised.

According to MetroWest, the project’s initial estimated cost of £58million has risen by so much because the full impact of works needed to run trains through Avon Gorge every half an hour had been underestimated. The organisation claims running trains at 50mph through the Gorge – which is needed for a half-hourly service – is more expensive and difficult to implement than running them at 30mph once an hour, as this is the speed currently in place along the existing Portbury freight line.

The council’s director of development and environment, David Carter, said: “The process we are suggesting and recommending is to look at stages A and B as they would significantly reduce the cost.

“We believe the work will be done and it will still be delivered in 2021, assuming the funding can be found.

“Stages A and B will still need to attract additional funding, but we believe there will be a significant reduction for A and B compared to C. However, until we have done the work, it is difficult to say exactly what that is.

“We are working with Network Rail and the Department for Transport to close that funding gap.”

For a full reaction to the announcement, pick up a copy of next week’s Times.