"She must and should understand what is Jan Lokpal Bill first and then speak on the issue", Hegde, a member of the Lokpal bill drafting committee, told reporters here.
Hegde has advocated that the Prime Minister and judiciary should be brought under the ambit of the proposed legislation.
Jayalalithaa may be dreaming that she will become Prime Minister in future and is opposing the idea of brining the office of Prime under the act, Hegde said.
He said state governments had no intention of fighting against corruption and called for social boycott of those who engaged in corruption.
Hegde was speaking after inaugurating a conference organised to create awareness on fighting against corruption, held at Dharwad, a nearby town.
Jayalalithaa had said she was against bringing the Prime Minister under the Lokpal's ambit as it would undermine his authority and pave way for a "parallel government."