Two Labour MPs have been referred to the party's disciplinary committee following allegations of sexual harassment, the party confirmed on Friday.
Allegations against Kelvin Hopkins and Ivan Lewis will now be considered by the party's National Constitutional Committee, which will decide whether further action should be taken.
However, alleged victims complained that they only learned about the decisions from the media and said the party was taking too long to investigate the claims.
Ava Etemadzadeh first lodged a complaint with the Labour Party in 2015 about former shadow front bench MP Kelvin Hopkins, alleging inappropriate behaviour.
"I am very unhappy with how the case has been handled," Etemadzadeh told BuzzFeed News, pointing out she first made a complaint in 2015.
"The very same time I made a complaint, Simon Danczuk was reported to the party and Corbyn set up an independent investigation into the allegations and kicked Danczuk out, whereas in 2016, despite knowing the allegations, and the whip warning him, he promoted Kelvin Hopkins to the Shadow Cabinet.
"I learnt from the media that my case has been referred to the NCC. It demonstrates that they are playing political games and covering up the case.
"I don't think political parties can be trusted with these issues. My experiences and others demonstrates that political parties cannot be trusted to deal with sexual harassment issues and we should have an independent reporting body to investigate these cases."
Labour MP Kerry McCarthy, who also made allegations against Hopkins, told BuzzFeed News she was unhappy with the way complaints had been handled. She said: "We need to review how these cases are handled so those involved know what’s going on, before the media, and that the case needs to be dealt with by the NCC as soon as possible.
"There was no good reason for delay before Christmas and there is no reason it can’t be dealt with quickly now."
A Labour Party spokesperson separately confirmed that a complaint against Ivan Lewis, first revealed by BuzzFeed News, would be referred to the NCC.
The delay in dealing with the cases, coupled with the leaking of information evidences the fact that sexual harassment allegations should have been dealt with independently, the complainants said.
It is understood that it may be several weeks before either cases are heard due to a backlog of complaints due to go before the NCC.
A Labour spokesperson declined to comment on the criticism from the alleged victims.
“After consideration of statements provided by the complainant and the respondent, the NEC’s Sexual Harassment panel has agreed that on the balance of the evidence the matter should be referred to a full hearing of the National Constitutional Committee," the spokesperson said.
"The Labour Party will not be commenting further on this case until the conclusion of that hearing.”
Labour Too, a campaign group which is encouraging women within the party to share accounts of sexual harassment, criticised the process: "It is unacceptable that complainants are finding out about the progress of their complaint from the media rather than from the Labour Party. It confirms our assertion that the process is not delivering the confidentiality that it promises, and this needs urgent reform.
This is why we are calling for a process that is independent from start to finish, which will provide the much needed reassurance and trust to the process that individuals who wish to make complaints need."