Amid demands for calling Prime Minister Manmohan Singh and Finance Minister P Chidambaram as witnesses before the Joint Parliamentary Committee (JPC) on 2G, BJP members in the panel on Thursday once again abstained from its proceedings.

During the last meeting of JPC on October 11, the BJP members had stayed away while accusing JPC Chairman P Chacko of failing to finalise the list of witnesses and include the Prime Minister and Chidambaram in it.

BJP has six members in JPC.

In July and September, BJP members had stormed out of the meeting accusing Chacko of being "biased" and accused Congress members of using foul language against them.

BJP Leader Yashwant Sinha, who is a member of JPC, had dashed off a letter to Chacko earlier this week saying that the body is of a "special nature" and, hence, a precedent can be set by calling the Prime Minister.

He had maintained the Prime Minister was directly involved in certain decisions on 2G spectrum allocation and "he and he alone" can answer some of the questions related it.

Sinha had also said the Prime Minister had offered to present himself before Parliament's Public Accounts Committee (PAC) on the same issue and, therefore, he should not have any objection to facing JPC.

BJP has clearly told Chacko that it will not attend the JPC meetings till the list of witnesses is finalised and the Prime Minister and the Finance Minister are summoned.

Chacko had earlier sought directions from the Speaker on the issue of summoning Chidambaram, but the Speaker had informed Chacko that the Committee has to first take a decision on the issue before approaching her and it was, therefore, "premature to intervene at this stage".