text: Marston Vale line These services ran on the Marston Vale line between  and :
  Performance
  Silverlink was categorised as a London and South East operator by the Office for Rail Regulation (ORR) and was one of the best performing TOCs in this sector with a PPM (Public Performance Measure) of 90.8% for the last quarter of the financial year 2006/7. Despite these figures, the Silverlink Metro franchise on the North London Line was regarded by frequent travellers as offering a poor service, with extremely congested trains and an unreliable service with some trains cancelled shortly before they were due to arrive. A London Assembly report said passengers found the service "shabby, unreliable, unsafe and overcrowded".
  Rolling stock
  Silverlink inherited a fleet of Class 117 and Class 121 diesel multiple units, and Class 313 and Class 321 electric multiple units, from British Rail.
  To replace the elderly Class 117s and 121s, which operated the Gospel Oak - Barking and Bletchley - Bedford services, seven Class 150 Sprinters were transferred from Central Trains in summer 1999; an eighth followed in 2006. Pending the Sprinters' arrival, Silverlink hired Class 31 locomotives from Fragonset to top and tail Mark 2 carriages on Bletchley - Bedford services in 1998/99.