The lawyers for property developer and former Newcastle mayor Jeff McCloy, who is challenging NSW laws banning political donations from developers, have told the court the ban is designed to bolster politicians' popularity "at the expense of even less popular community members".

Mr McCloy, who admitted at a corruption inquiry to giving wads of cash to Liberal candidates before the last state election, is seeking to have the donations ban struck down on the basis it infringes the implied freedom of political communication in the Constitution. His challenge extends to the prohibition on donations from the tobacco, alcohol and gambling industries.

Mr McCloy's legal team, headed by David Bennett, QC, says in written submissions to the High Court that the laws may not serve the end of preventing corruption. Rather, the laws are "an attempt to prevent socially undesirable persons from being seen to contaminate political parties and candidates with their influence".

"The legislative intention is thus not to preserve public confidence in the political process, but rather an attempt to bolster the popularity of its central actors [politicians] at the expense of even less popular community members," the submissions say.

Mr McCloy's legal team says there have been "only eight" instances in NSW over 25 years in which commissions of inquiry have "found corruption to have occurred in connection with property developments".

It cannot be concluded from the fact a person is a property developer that they pose "such a risk to the integrity of the political process" that they should not be allowed to make political donations, they say. The same conclusion might be made about "trade unions, banks, lawyers, accountants, financial advisers, real estate agents, media proprietors, supermarket chains, or pharmaceutical companies".

They add the requirement that donors publicly disclose their payments is enough because "the light of publicity is the surest scourge of potential corruption".

Mr McCloy is also challenging the legislative cap on the amount that may be given by donors. His legal team says there is no reason to conclude that "even a very large donation necessarily entails some kind of quid pro quo" and having political influence "does not mean purchasing specific outcomes; it only entails an increased chance of being heard".

The High Court ruled in December 2013 that a similar ban on donations by trade unions and corporations was invalid. The case is expected to be heard in June.