London Underground is in talks with the European Organisation for Nuclear Research (Cern) about the possibility of using the 23km tunnel of the Circle Line to house a new type of particle accelerator similar to the Large Hadron Collider in Geneva.
Particle physicists believe the existing tunnel can be adapted to take a small-scale "atom smasher" alongside the passenger line at a fraction of the cost of building a new tunnel elsewhere in Europe. They are understood to have approached London Underground with a view to announcing a feasibility study later this year.
Specialist engineers commissioned by Cern have already produced a preliminary report, seen by The Independent, which proposes installing supercooled magnets and collision detectors at strategic positions on the Circle Line. The main collision experiment will be sited at the newly refurbished Westminster Station, directly below Portcullis House, the offices of more than 200 MPs.