BP and the Department of Justice have defended the plea agreement, saying it's the harshest option available in assessing criminal punishment for the blast, which killed 15 workers and injured more than 170 others.
Ralph Dean, who along with his wife Alisa, was injured while working at the plant has asked to speak on Monday.
In a victim impact statement he filed with the Department of Justice last week objecting to the plea agreement, Ralph Dean said his wife suffered serious and permanent injuries, including head injuries and internal burns to her lungs.
"Even the smallest physical exertion now taxes her physical ability ... and the activities she once enjoyed are out of reach for her," he wrote. "I have been forced to stop work entirely in order to be home to care for her."
In her statement, Alisa Dean accused BP of breaking a promise to pay her medical bills after the couple's lawsuit against the company was settled. She said a hospital lien for more than $600,000 was put on her after BP stopped paying her bills. The lien was later removed. The Deans have a lawsuit pending against BP for the medical bills.
"I know that others have also been mistreated by BP in this way, and I do not want BP to get away with a reputation of having been generous and responsible to the victims of the explosion," she wrote.
The parents of Susan Taylor, who was killed in the blast, also angrily objected to the plea. They were not scheduled to speak on Monday but submitted their victim impact statements last month.
Taylor's family has already settled a lawsuit against BP for her death.
"How can you live with yourself when I can't even know how to go on without my baby?" Mary Ann Duhan, Taylor's mother, wrote in her statement. "I pray every minute of every day that every one will pay from the top of the company to the person who pushed the wrong button, for what you have done."
Taylor's father, Ronald Duhan, said there was "no penalty great enough" for what BP did.
"My prayer is that the court will sentence all of them like any other common mass murderers and that God may take pity on their souls," he wrote.
In October, BP and the Justice Department agreed the London-based oil giant would plead guilty to a felony, pay a $50 million fine and be on probation for three years for its role in the explosion.
The fine and plea were part of an agreement by BP to pay $373 million to settle various criminal and civil charges.
BP was set to formally enter its guilty plea in court in November. But several attorneys for blast victims objected and the judge agreed to let them voice their complaints.
In their final court filing before next week's hearing, attorneys for the blast victims on Thursday reiterated many of their criticisms of the plea deal. They called the proposed fine "trivial" and said the plea deal doesn't push to improve safety at the plant or fully detail BP's history of safety violations.
In a statement, BP reiterated it has accepted responsibility for what happened, worked hard to improve safety at the plant and has fully cooperated with the criminal investigation.
"The plea agreement results in harsh punishment," BP said. BP has said it's paid more than $1.6 billion to compensate victims.
The explosion at the plant, about 40 miles southeast of Houston, occurred after a piece of equipment called a blowdown drum overfilled with highly flammable liquid hydrocarbons.
The excess liquid and vapor hydrocarbons then were vented from the drum and ignited as the isomerization unit -- a device that boosts the octane in gasoline -- started up. Alarms and gauges that were supposed to warn of the overfilled equipment did not work properly.
The U.S. Chemical Safety and Hazard Investigation Board, one of several agencies that investigated the accident, found BP fostered bad management at the plant and that cost-cutting moves by BP were factors in the explosion.
