The firm, in its plea, said the provision was liable to be "struck down" as a public servant who makes error in judgement and a government official who abuses his or her position are "painted with the same brush".
"The provision is thereby liable to be struck down on the ground of treating unequals equally, in as much as public servants who may make an error of judgement, as well as dishonest public servants who may abuse their position to confer pecuniary gain are treated within the same class and painted with the same brush," it said.
The firm has said that section 13(1)(d)(iii) of the Prevention of Corruption Act was unconstitutional as it "criminalises an exercise of discretion by government servants without any further requirement of mens rea (criminal intention), dishonesty, quid pro quo or illegal gratification on the part of the public servant.
"Apart therefrom, the provision is vague and arbitrary. The provision also impinges on the fundamental right to carry on business by criminalizing legitimate business activities without anything more."
The provision says that a person, holding office as a public servant, can be tried if he obtains "for any person any valuable thing or pecuniary advantage without any public interest".
It said that by completely omitting the need for mens rea, this provision fails to have any rational nexus with the objective of the statute which is to prevent dishonest act by public servants.