Four senators, who had complaints made against them under the Ethics in Public Office legislation, have responded to the Seanad Committee on Members' Interests.
The Committee will meet on Monday and decide whether it has sufficient information to proceed with its inquiries.
It is not clear yet whether more time may be provided for additional information to be submitted.
Each of the senators was asked to provide a detailed written response by 23 August.
Three of the senators, Ivor Callely, Larry Butler and Ann Ormonde were asked to deal with complaints regarding expenses claims they made.
In the case of Senator Callely the complaint relates to mobile phone expenses.
Senators Butler and Ormonde were asked to deal with complaints concerning travel expenses.
The fourth Senator, Independent member Rónán Mullen faced a complaint over an anecdote he told regarding the expenses regime in Leister House.
He objected angrily to being 'lumped in' with the other three senators as there was no complaint against him regarding his expenses.
Senator Mullen publicly called on the Committee to deal with the complaint against him separately to those against other senators.