The special Sewol-ho ferry bill aims to create an inquiry panel that will determine the exact cause of the deadly sinking in mid-April which left 304 people dead or missing.
The rival parties disagree on whether to give the inquiry panel prosecutorial powers, meaning the bill has been sat in limbo for weeks.
The ruling Saenuri Party is against the idea of giving the inquiry panel prosecutorial powers and says the time for negotiations is over.
"I'm speechless. What are we getting out of this political deadlock? What's the essence of democracy? What are we going to say to our future generations?"
Saenuri Party lawmakers say that giving such overreaching powers to authorities other than state prosecutors would set a dangerous precedent.
Prosecutorial powers refer to special legal prerogatives, such as the right to ask the courts for search warrants or detain suspects.
The main opposition party, New Politics Alliance for Democracy, and the bereaved families say the panel will be unable to reveal the root causes of the disaster without such powers and blame the bill's delay on the ruling party.
"Our party has been trying to offer leadership to the parliament. I've tried to break the impasse and I've done my best to cooperate."
Last week's compromise between rival parties' floor leaders did not give the inquiry panel legal powers, which prompted the victims' families and some opposition lawmakers to demand the deal be nullified.
If the political discord continues,.. the ruling party may find it much more difficult to pass urgent bills while the opposition party could be facing yet another leadership crisis.
Ji Myung-kil, Arirang News.