A320
Flight Crew Air Transport Pilot (ATP); Flight Crew Flight Engineer; Flight Crew Instrument; Flight Crew Multiengine
Flight Crew Last 90 Days 160; Flight Crew Total 23820; Flight Crew Type 7900
Situational Awareness; Communication Breakdown
ATC Issue All Types; Conflict Ground Conflict; Less Severe; Deviation / Discrepancy - Procedural Clearance; Ground Incursion Runway
Air Traffic Control Issued New Clearance; Flight Crew Requested ATC Assistance / Clarification; Flight Crew Became Reoriented
Airport; Procedure; Human Factors
We were cleared to leave the ramp and taxi to the runway. We were told our sequence was to follow the MD88 ahead and monitor the tower which we did. Approaching the taxiway the MD88 started taxiing to cross the left runway which was being used as a taxiway as there was a tug pulling an aircraft stopped on the runway. So as previously cleared we continued to follow the aircraft ahead.Approaching the runway Tower called our flight number so I stopped with nose slightly on the runway. My co-pilot then told Tower our clearance was to follow the MD88 and monitor the tower which we were doing. The controller then said he has a phone number to call for possible runway violation. We continued on with no further incident. There was no threat to safety in anyway. The clearance to sequence and follow the MD88 superseded the one given to us on the ramp. We were never told to hold short of a taxiway or the left runway with the second clearance. There was a definite communication failure on both parties; ATC and us. With the tug and aircraft stopped on the left runway the runway was obviously not active. In the future with this type of communication I will clarify the intent.
A320 Captain reported being issued taxi instructions to follow another aircraft and following the aircraft onto a runway to cross; but that was not ATC's intention.