The chair of a public inquiry into Labor's plans to abolish refundable franking credits, Liberal MP Tim Wilson, says he was "pleased" to hear ex-Labor candidate Marg D'Arcy's comments in support of Labor's policy because it did nothing but undermine Labor's campaign.

"Ms D'Arcy single-handedly disproved all the Labor misinformation and attempts to shut down this inquiry – anyone who wanted to attend was entitled to have their say," Mr Wilson said.