AN A319 BEING MARSHALED IN TO THE GATE AT PHL HAD TO STOP ABRUPTLY TO AVOID A COLLISION WITH A CART.

Narrative

WHILE TAXIING IN TO GATE X; WE HAD TO STOP SHORT DUE TO GATE Y HAVING TO WAIT FOR A GND CREW TO PARK THEM. OUR GND CREW WAS NOT PREPARED WHEN THE ACFT AT GATE Y HAD MOVED FORWARD FOR US TO PROCEED. THEY WERE BASICALLY STANDING IN THE SHADE UNTIL WE GOT INTO A POS WHERE THEY COULD COMMAND A STOP. I SEE THIS AS A 'POWER PLAY' BY THE GND CREW. MIGHT THEY CONSIDER A 100000+ LB ACFT STARTING AND STOPPING AND ALL THE RAMIFICATIONS THAT COME FROM THAT -- FUEL BURN; BRAKING; JETBLAST; JUST TO NAME A FEW. ONCE OUR GND CREW DECIDED IT WAS TIME FOR US TO SAFELY PROCEED TO THE GATE; THEY GAVE THE TAXI SIGNAL FOR US TO MOVE FORWARD. THE MARSHALLER WAS UNDER THE JETWAY; STILL IN THE SHADE WHILE BRINGING US FORWARD. WE PROCEEDED FORWARD; IN A SAFE MANNER; WHEN OUT OF THE CORNER OF MY EYE TO THE LOWER R; A TUG WITH 1 CART ATTACHED; BEING DRIVEN; DARTED IN FRONT OF THE R (32) ENG. I IMMEDIATELY LOCKED THE BRAKES. THE DRIVER CONTINUED ON. I DID NOT GET A NUMBER FROM THE TUG. AS I DID THE POSTFLT WALKAROUND; I SPOKE WITH ONE OF THE GND PERSONNEL. HE SAID HE TOLD THE DRIVER OF THE TUG TO TURN L AND STAY AWAY OF US (THE ACFT) AS WE CAME IN. OBVIOUSLY; THE DRIVER DID NOT LISTEN; AND TURNED R -- DIRECTLY INTO US. GND PERSONNEL NEED TO KEEP THE ACFT ROLLING SAFELY TO THE GATE BY BEING PREPARED. TUG DRIVERS NEED TO BE MORE VIGILANT OF LARGE NOISY ACFT TAXIING TO THE GATES. ALL THIS STOPPING AND STARTING GIVES THE TUG DRIVERS A FALSE SENSE THAT IT IS SAFE TO PROCEED AROUND A MOVING ACFT.