The National Anti-corruption Commission (NACC) says it has done enough to ensure criminal prosecution of former prime minister Yingluck Shinawatra and will not comply with requests to gather more evidence.
NACC secretary-general Sansern Poljiak said on Saturday that his office had completed its task of interrogating witnesses and looking into the evidence in connection with the former government's failed and costly rice-pledging programme.
"We won't take the advice of the Office of the Attorney General (OAG) to talk to more witnesses and look into other evidence because they have nothing to do with the issues we used to prosecute [Ms Yingluck]" for dereliction of duty, he said.
The NACC will, however, discuss the OAG's suggestions when it meets on Monday.
In any case, the OAG's stance has now become clearer. "If the attorney general and the NACC stand their ground, no joint resolution can be reached," added Mr Sansern.
"If the attorney general wants to investigate further into issues other than what we laid on the table, we can't agree to that. However, we'll have to wait until the joint meeting, which happens to be our last, to see whether the OAG will prosecute her on our behalf."
By law, the NACC must send a case to the OAG for prosecution if it decides the case has grounds.
In Ms Yingluck's case, the OAG wanted the NACC to look more deeply into government-to-government rice deals to establish whether the sales had really taken place, as witnesses had contradicted one another.
"G-to-G deals have nothing to do with establishing Ms Yingluck's guilt," said Mr Sansern. "Actually, they have nothing to do with this case.
"Her case involves her failure to stop the damage incurred by the scheme while the G-to-G deals are being dealt with in the corruption case against former commerce minister Boonsong Teriyapirom and Pum Sarapol, his former deputy. So why the OAG wants us to investigate the G-to-G case now is beyond us."