Network Rail punctuality statistics reveal that 58% of First ScotRail trains do not arrive on time and more than half of virgin Trains on the West Coast Main Line are late.
Both firms are below the UK average of 67% punctuality, with the best performance achieved by Chiltern.
Using the Network Rail 'Right Time' performance figures a train is on time if it arrives within 59 seconds of schedule, however the Office of Rail Regulation uses figures for Public Performance Measure, which allows up to five minutes for a short distance service and 10 minutes for a long distance trip.
Only 47.4% of services operated by Virgin Trains on the West Coast were on time in the 12 months ending August 17 2013, according to "right-time" statistics from Network Rail (NR).
Under PPM, a short-distance train is only deemed to be late if it arrives five minutes or more after the scheduled time, while a long-distance train has to arrive 10 minutes or more behind schedule to be considered late.
However, while the figures are published for train operators across the UK, around 60% of delays to train services are attributed to Network Rail, which has been repeatedly warned by the ORR about its punctuality performance.
ScotRail said: "More than half of the delays in the last 12 months were beyond our control, but we are working closely with Network Rail on measures to bring 'right time' performance back up to previous high levels."
A spokesman for Virgin Trains said: "We are unhappy with Network Rail's provision of the reliable infrastructure we need to run punctual train services."