The CBC said that the ban would contravene EU law and would lead to worse environmental impacts as shoppers would switch to heavier alternatives.
In addition, the group argues, plastics recycling rates could suffer as biodegradable bags cannot be recycled as the degrdaable polymers weaken non-degradable polymers when mixed.
Italy has banned retailers from handing out new standard single-use plastic carrier bags – once current stocks have run out – as of 1 January.
They are, however, allowed to distribute bags made from biodegradable polymers, cloth or paper. Italy uses around 20bn single-use carriers every year, compared to around 6bn in the UK.
The European plastics trade body, EuPC, said earlier this week that it would fight the ban on the grounds that it breaches the Packaging and Packaging Waste Directive.
CBC chairman Paul Marmot said: “We fully support our European partners at EuPC in mounting a legal challenge to the Italian moves at EU level.
“It is a great shame that the Italian government did not take heed of more than two years of investigations by the Scottish Parliament when they were placed under similar but wholly misguided environmental pressures.”
Barry Turner, chief executive of Pafa, which represents flexible plastics manufacturers, said: “There are serious flaws in the arguments used against plastic bags and, with no scientific support for such moves, the unwarranted attacks on the plastics industry clearly contravene EU law.
“In all of our work, including the defeat of the Scottish Parliament Bill, we have come across no evidence anywhere in the world that bans or charges for plastic bags will guarantee a fall in overall environmental impacts.”
Turner pointed to the voluntary deal struck in the UK among retailers, which has led to a near 50% overall drop in the use of single-use plastic bags, as a positive approach to reducing the environmental impacts of plastic bags.