Caretaker Prime Minister Yingluck Shinawatra is expected to send her representatives to acknowledge a charge of negligence of duty on her behalf.
A source close to the premier said Ms Yingluck is unlikely to meet the National Anti-Corruption Commission (NACC) face to face and will answer the allegation in writing.
The anti-graft agency decided to press a charge of negligence of duty against Ms Yingluck over her role in the debt-ridden rice-pledging scheme and summoned her to answer the charge next Thursday. Ms Yingluck chairs the the National Rice Policy Committee responsible for implementing the scheme.
In its decision to charge Ms Yingluck, the NACC claimed the premier was aware of irregularities but failed to correct them.
The charge is part of the impeachment proceedings against the prime minister who was the chief target of the opposition's no-confidence debate in November last year.
Ms Yingluck is required to suspend her duties if the NACC decides to indict her. A decision is expected in mid-March.
Senate Speaker Nikhom Wairatpanich said yesterday the Senate may have a quorum problem if the NACC proceeds with the ouster bid in March.
An impeachment of the prime minister requires three-fifths of senators.
Currently a group of 50 senators are accused of misconduct in connection with a charter amendment to make the Senate fully elected.
He said the quorum problem will arise if the NACC indicts these senators.
It is not clear if the entire Senate or just the remaining members are needed to vote in an impeachment process, he said.
According to Mr Nikhom, the Senate can still meet on the impeachment even though the term of elected senators expires on March 2. The elected senators will carry on until a new batch of elected senators is endorsed following a March 30 Senate poll.
However, Mr Nikhom noted Ms Yingluck has the right to continue working as long as she is not indicted by the NACC.
Caretaker Foreign Minister Surapong Tovichakchaikul said the NACC's move against Ms Yingluck was not unexpected and former prime ministers Thaksin Shinawatra, Samak Sundaravej and Somchai Wongsawat had gone through this before.
Mr Surapong called on the protesting farmers not to be manipulated in a political game.