"Under the Lok Sabha Rules, PAC cannot call a Minister, much less the Prime Minister. (The) Prime Minister's offer therefore, has no meaning," she tweeted.
Her comments come a day after Singh wrote to PAC chairman Joshi expressing his readiness to appear before the panel, which is probing the 2G Spectrum scam.
Joshi, who does not seem to be very enthusiastic about the campaign for a JPC, yesterday said that the PAC will take an "appropriate decision at an appropriate time" on Singh's offer after going through rules and procedures and in accordance with them.
Swaraj said the "scope of PAC is totally different from that of JPC. While PAC deals with accounts, JPC deals with accountability and governance."
Under Speaker's Direction 99 under the rules of procedures and conduct of business in Lok Sabha, the 22-member PAC cannot call a minister to give evidence or for consultations in connection with the examination of accounts by it.
The chairman of the committee, however, may have an informal talk with a minister on the subject under consideration by the committee.
Since the Prime Minister's offer is unprecedented in its nature, the Speaker may have to devise a procedure on how the committee could accept it.
BJP will attend all party meet on JPC