Under the scheme, a new passenger service links some of Northumberland's major population centres in Ashington, Bedlington and Blyth to the nearby city of Newcastle upon Tyne.

As coal production increased during the remainder of the 19th and early 20th centuries, the network of railway lines in this part of the region under the control of this company and its successors continued to expand, reaching what would become Ashington and Newbiggin by 1872.

As of 2022[update], around five freight services a day were operating the branch, providing the biomass (former coal-fired) power station at Lynemouth, at the northern end of the line, with wood chips from the Port of Tyne.

[12] The South East Northumberland Rail User Group began a campaign to reopen the remaining freight lines between Benton Junction, Morpeth, Bedlington and Ashington in March 2005.

[17] The GRIP 2 study, which NCC received in October 2016,[18] confirmed that the reintroduction of a frequent seven-day a week passenger service between Newcastle and Ashington was feasible and could provide economic benefits of £70 million with more than 380,000 people using the line each year by 2034.

[19] The 2016 GRIP 2 study envisaged a project (at the time referred to as the Ashington, Blyth & Tyne Line), at an estimated cost of £191 million,[19] involving construction of new or reopened stations at Northumberland Park (for interchange with the Tyne and Wear Metro), either Seghill or Seaton Delaval, Newsham, Blyth Park & Ride, Bedlington, Ashington and Woodhorn (for the Woodhorn Colliery Museum and Northumberland Archives) with a potential end-to-end journey time of 37 minutes.

[26] On 8 February 2019, the council chartered a train from Northern that carried the then Secretary of State for Transport Chris Grayling and other dignitaries over part of the route (now rechristened the Northumberland Line) between Morpeth and Newsham,[27] after which NCC announced an additional £3.46 million in funding for a further business case and detailed design study[28] (equivalent to GRIP 3)[29] to be completed by the end of 2019.

[28][30] Revised proposals, released in July 2019, were reduced in scope from the plan considered in the 2016 GRIP 2 study and proposed a four-phase project[31] to reduce the initial cost; the first phase, at an estimated £90 million,[28] was to introduce an hourly passenger service[26] to serve new or reopened stations at Northumberland Park, Newsham, Bedlington and Ashington and would have included some line-speed upgrades, extension of the double track section further to the south of Newsham, creation of turn-back facilities at Ashington and some level crossing upgrades or closures.

[36] The allocation of a further £34 million of UK Government funding for the project in January 2021 enabled the necessary land to be purchased, detailed designs to be prepared and some early preparatory and site works to begin.

[39] During 2021, planning applications were submitted for the proposed stations: for Northumberland Park[40] and Ashington in February;[41] for Blyth Bebside[42] and Bedlington in March;[43] for Seaton Delaval in June;[44] and for Newsham in September.

[45][46] A further planning application was submitted for the replacement of a pedestrian crossing in Ashington with an underpass, on 24 September 2021,[47] but strong local opposition meant that, as of June 2022[update], it was unclear whether this would ultimately be built as part of the project.

[61] The planned new passenger service will begin at Newcastle, before heading north along the East Coast Main Line to Benton Junction,[10] with an intermediate stop at the existing Manors station.