Some forms of 2,4-D have been banned in Australia.

The Australian regulator APVMA has cancelled registrations of 2,4-D herbicides of the "high volatile ester (HVE)" type on the grounds that they pose an unacceptable risk to the environment.

APVMA is still working out what to do about the forms of the herbicide that are not HVE type.
http://www.apvma.gov.au/products/review/current/2_4_d.php

More information:
http://www.psnews.com.au/Page_psn375f7.html

2,4-D has been the go-to herbicide of the biotech industry since the spread of glyphosate-resistant weeds has challenged the viability of glyphosate herbicides and of GM crops tolerant only to glyphosate. The industry has started to produce GMOs that are tolerant to 2,4-D as well as glyphosate.

Dow's 2,4-D-tolerant corn is facing stiff opposition in the US:
http://www.reuters.com/article/2013/01/18/dow-biotech-idUSL1E9CIBN320130118