The fresh delay to HS2 may help campaigners in their fight against a controversial project to build a large railway depot on the outskirts of Northampton.
The Northampton Gateway strategic rail freight interchange's (SFRI) business case was predicated on the high-speed rail line creating more space on the West Coast Main Line.
But because phase one of HS2 may not be built until 2031, South Northamptonshire MP Andrea Leadsom has written to Transport Secretary Grant Shapps to take this into account when deciding on the SFRI.
"Should the delivery of HS2 be delayed (or, indeed, cancelled following the Oakervee Review), then this would have a substantial impact on the business case for Northampton Gateway, meaning fewer available freight paths and greatly increased road-based freight movements," the letter reads.
Northampton Gateway would see developer Roxhill build a large rail depot built on land east of the West Coast Main Line and next to junction 15 of the M1 between Milton Malsor and Collingtree.
Campaign group Stop Roxhill was set up to fight the plans, arguing there is insufficient need to 'wipe out' hundreds of acres of countryside and the area is not earmarked for development.
An 18,000-strong petition in opposition to the scheme and another close-by called Rail Central has been given to the Department for Transport.
But Roxhill claims the 'next-generation' SFRIs are needed to cope with demand and the locations are the 'best in the UK', while improvements will be made to infrastructure in the surrounding area as a result.
The secretary of state is currently considering the planning inspectorate's recommendation on whether or not to grant a development consent order for the scheme.
But Mr Shapps' recent admission in the House of Commons that the HS2 line between London and Birmingham should be delayed to 2026 or even 2031 has thrown doubt on Northampton Gateway.
Rod Sellers, from Stop Roxhill, said: "Central to the ‘strategic’ case being made by the developer has been the claim that there would be sufficient capacity on the rail network to cope with the volume of rail freight needed to justify Northampton Gateway as a genuine SFRI rather than just another road based warehouse development.
"At the various examination hearings, Network Rail has been unable to confirm this capacity and now new doubts on the progress of HS2 raise further questions.
"This is a 5m sq ft speculative warehouse development, masquerading as essential infrastructure in order to bypass local planning policies.
"It is not a project in the ‘national interest’ and will destroy hundreds of acres of productive countryside creating yet more traffic and pollution on an already overstretched road network”.
A spokesman for Ms Leadsom said Mr Shapps is yet to respond to her letter from September 3.