It wants the EC to suspend the endorsement of the former auditor-general.
Led by Songchai Vimolbhattranond, the June 24 group claimed Khunying Jaruvan had won because appointed senator Paiboon Nititawan had spoken on the People's Democratic Reform Committee protest stage in a manner that had put other senate candidates in Bangkok at a disadvantage.
The group alleged Mr Paiboon had abused his authority by campaigning for Khunying Jaruvan and saying he would like to have her work with him as a team in the Senate.
The complaint alleged this violated Section 122 of the charter and Section 53(5) of the amendment to Section 57.
Section 122 stipulates: "Members of the House of Representatives and senators are representatives of the Thai people without being bound by any mandate, entrustment or dominance, and shall honestly perform the duties for common interests of the Thai people without any conflict of interest."
The group also asked that election commissioner Somchai Srisuthiyakorn be excluded from consideration of its complaint, questioning his impartiality.
Mr Songchai also said a senator was an honourable person, but Khunying Jaruvan had been charged in five cases now being considered by the National Anti-Corruption Commission (NAAC).
In the most recent case, she was accused of misappropriating state funds allocated for an Auditor General's Office seminar which turned out to be no seminar but a kathin (robe offerings for monks) ceremony sponsored by herself
In another case, she was accused of asking for free air tickets from Thai Airways International for her daughter and sister to accompany her on an overseas seminar trip, and approving their allowances for the seminar as if they were officials.
The group questioned whether a person with such "flaws" was qualified for the job of senator, and asked the Election Commission to consider its complaint as soon as possible.
Khunying Jaruvan was a member of the now-defunct Assets Scrutiny Committee established by the 2006 coup makers to probe the wealth of politicians, especially Thaksin Shinawatra.