Businesses are calling on governments to step in to mediate a damaging ports dispute, warning that months of delays to shipped goods, from clothes to cars and lamb chops, are causing severe harm to reputation and finances.

Melbourne manufacturer Craig Lang, who employs 12 workers to produce hardware for sliding doors at his business Tomma, said the three months of industrial action at DP World ports around the country had left him waiting eight weeks for more than $500,000 worth of critical parts from overseas.