Supporters argue the project could be scaled (for example, Liverpool to Edinburgh) while preserving its transformative potential, and they view political will as the main hurdle.

While inspired by The Line, Williamson emphasizes a UK–Ireland scale focused on interconnected urban travel rather than isolated, competing investments.

Trains would be 50 meters long, run on elevated viaducts, and operate every five minutes at speeds up to 300 mph, delivering a maximum travel time of about 90 minutes between any two of the nine cities.

A historical precedent exists from two decades ago under a Labour government that proposed a similar concept but did not advance, underscoring the need for renewed political leadership.

Proponents claim 12 million people would be within 90 minutes of the network, positioning the UK as a megaproject catalyst capable of surpassing existing transport ambitions in vision and impact.

A new concept called The Loop envisions a 740-mile high-speed rail line linking nine major UK and Ireland cities—Dublin, Belfast, Glasgow, Edinburgh, Newcastle, Leeds, Manchester, Liverpool, and Bangor (Wales)—to transform regional travel.

Estimated construction cost is about £130 billion, and the concept will be formally presented at the Royal Academy Summer Exhibition in London, though it currently lacks government backing.

The proposal would cross the Irish Sea twice, requiring tunneling or bridging at the Glasgow–Belfast and Dublin–Bangor links.

The Loop draws inspiration from Saudi Arabia’s NEOM Line but faces skepticism due to the scale and history of delays in similar megaprojects.

The project is positioned at roughly £130 billion, with the elevated railway design intended to minimize ground-level disruption while pursuing high-speed service.

Proponents argue the Northern Loop would boost economic connectivity and collaboration between northern cities, driving significant regional benefits.

The Loop is discussed alongside broader UK transport planning, including Northern Powerhouse Rail, with acknowledgment of ongoing debates around major rail projects.