Auckland Transport is accused of softening up rail commuters for slower trips on new electric trains by adding three minutes to its western line timetable.
The council body, which denies the claim, says departure times to Newmarket and Britomart will be "up to three minutes earlier" from Tuesday - though arrival times will remain unchanged.
Although the timetable applies to diesel trains, transport campaigners fear it is a tactic to lessen disappointment if electrics due full-time in the west by the end of July prove as slow as early tests have indicated.
Transportblog editor Matt Lowrie said yesterday rail chiefs seemed to be "pre-emptively slowing down the western line timetable ahead of running the EMUs [electrics] as their testing has revealed them to be much slower than the diesel trains".
Industry sources had told him the new trains were running on average five minutes, and up to eight minutes, slower than diesels between Henderson and Britomart on test trips.