In 2000, East Coast Main Line operator ''Great North Eastern Railway'' (GNER) began looking for an additional fleet of trains to augment its existing InterCity stock. The company considered placing a follow-on order from that of Virgin West Coast's, for a small batch of Class 390 ''Pendolino'' units, but it was soon deemed that this would be too time consuming, and a quicker solution was needed. The answer lied at North Pole Depot: the redundant Regional Eurostar sets. The decision was taken to lease three formations for any one day, within the number range 3301 to 3306 and 3309 to 3312. Thus, specific units were not selected, but rather, the agreement hinged upon EPS providing any trio of formations. £2 million was spent ''clearing'' the Class 373 fleet for use between Doncaster and Leeds, but the exercise proved far swifter than ordering brand new stock. As for the remaining Eurostar formations, half sets Nos. 3307 and 3308 were retained at North Pole Depot as a source of spare parts, whilst half sets Nos. 3313 and 3314 were kept back to test the CTRL. The short-formed sets commenced service on the East Coast Main Line in summer 2000, their sheer length proving that Kings Cross could only just about accommodate them. The formations lasted in this domestic capacity until 10th December 2005, after which they were returned to North Pole Depot, pending a new use. In the following year, it transpired that the Regional sets were this time bound for French domestic use. For GNER, in place of the now off-lease Regional sets, refurbished HST formations would be drafted in, cascaded down from Midland Mainline's "RIO" service. In brief, the "RIO" service operated between St Pancras and Manchester, and was put into place by the Strategic Rail Authority in May 2003, during the modernisation scheme on the West Coast Main Line.
"Regional" Class 373 Formations
All the above complete formations were to be leased to SNCF for use on the Paris to Lille shuttle service. This would allow the French rail operator to redeploy a number of TGV sets elsewhere; the lease on the Regional Class 373s extended into 2011. Half set No. 3307 was also destined for France, but as a source of spares, whilst its twin, No. 3308, would be retained at North Pole Depot in the same role. Half sets Nos. 3313/3314 are also being kept on the British side of the operation to test Phase 2 of the CTRL; it was this pair which had broken the British record for the fastest train ever to run, reaching 208 MPH on 30th July 2003 on Phase 1 of the CTRL. In France, the Regional sets have joined a trio of "Three Capitals" Eurostars which are already in domestic use. These SNCF-owned units include Nos:
These were subsequently re-branded with ''TGV'' on their sides, but the units continued to turn up on Chunnel workings. To ensure this did not happen again, all six half sets had their front yellow warning panels removed and their third rail collecting shoe gear disengaged.
From the outset, the route from London Waterloo took TMSTs via Beckenham, Bickley and Petts Wood Junctions, giving access to the latter half of the Charing Cross to Tonbridge line via Orpington. From 8th January 1996, international trains served Ashford International on this route, although this station was then better served by these workings on the opening of part of the new dedicated Channel Tunnel line from Fawkham Junction on the ''Chatham'' main line on 28th September 2003