High Speed 2 (HS2) has reached a major milestone as the giant tunnelling machines completing the 10-mile Chiltern tunnel finished their final journey, marking 80% completion for Phase 1 of the project.

The two machines, Florence and Cecilia, have spent nearly three years underground, creating the longest tunnel on the route between London and Birmingham. The project, though controversial due to rising costs and the cancellation of the northern leg, is now entering its final integration phase.

"This is a historic moment for British engineering," said the HS2 CEO. "We are now moving from heavy civil engineering to railway systems, bringing us one step closer to transforming travel between our two largest cities."

Critics remain focused on the £67 billion price tag for the remaining Phase 1, but supporters argue the capacity relief on the West Coast Main Line will provide generational benefits for UK freight and commuter services.