The European Commission will vote due on whether to or not to extend authorisation for the use of glyphosate in the EU on the 23 June.
In statement it said it would support a ban for contractors, if sufficient evidence of harm to human health were proven:
"Whilst BALI would not want to see this highly effective chemical withdrawn from use by its members and other amenity horticulture professionals carrying out weed control, it would unequivocally support its immediate withdrawal if sufficient scientific evidence from acknowledged and respected expert bodies was produced that prove it to be carcinogenic and therefore harmful to human health", it said.
BALI warned that removing what it said had been "an extremely effective and cost-efficient method [of weed control] which has kept costs down for clients and particularly for local authorities struggling with stringent budget cuts".
It added a ban was likely to lead to "more labour-intensive methods of controlling weeds" and would have an impact on the "level of control" possible in parks and public spaces.
In the short term, and in the absence of a scientific consensus on the effects of glyphosate on human health, BALI said it supported a ban on its sale to domestic users.
"BALI members operating in the public sector are already working collaboratively with their clients to trial alternative methods of weed control", it said.
"BALI hopes that, should glyphosate be withdrawn, sufficient time is given to the industry to adjust. In the event that glyphosate is withdrawn later this month BALI will work closely with its members to signpost them towards potential alternatives."