A Tennessee death row inmate refused a last meal after losing a last-ditch effort to halt her execution for a gruesome murder she committed when she was just 18. 

Christa Gail Pike, 50, is scheduled to be put to death by lethal injection on Wednesday morning for the 1995 slaying of 19-year-old Colleen Slemmer in a fit of jealous rage.

She is now refusing a last meal, according to the Tennessee Department of Correction, after state Governor Bill Lee denied her clemency request and the US Supreme Court declined to stay the execution.

Supreme Court justices made the decision less than one day before the deadline, with no explanation for their decision, The Hill reports.

Meanwhile, Governor Lee said he decided not to intervene in the case 'after deliberate consideration of Christa Gail Pike's request for clemency and after a thorough review of the case.'

Pike's lawyers said in the aftermath they were 'deeply saddened and heartbroken' by the governor's decision.

'Moving ahead with her execution puts the State of Tennessee on singular footing,' they said in a statement to Fox 17. 

'Christa will be the first person Tennessee executes in the modern death penalty era who was a teenager at the time of the offense, and the first woman executed by the state in more than 200 years.'

Prosecutors have said Pike feared Slemmer was a romantic rival and lured her to a secluded area where she and her boyfriend, Tadaryl Shipp, tortured and killed their classmate.

The case gained widespread attention because of the brutality of the killing, the ages of the perpetrators and because a satanic symbol was carved into the victim's body.

Pike does not deny her guilt, but her attorneys and supporters argue a death sentence is not appropriate for a crime committed at that age by a teenager with untreated mental illness after a childhood of brutal sexual abuse and neglect. 

In a desperate attempt to stay the execution, the lawyers also challenged the state's lethal injection protocol, arguing it would cause her needless suffering in violation of the Eighth Amendment, WATE reports.

Alternatively, the lawyers suggested Pike be hanged, but the Supreme Court ruled that hanging was not feasible and did not reduce the risk of severe pain. 

Pike's lawyers have since lamented how she 'was failed by people that should have shown her care and meaningful intervention.

'Instead, her childhood was marked by repeated, documented rape and sexual abuse, neglect and violence,' they claimed in their statement on Tuesday.

'The 18-year-old girl suffering from severe mental illness and near-debilitating trauma no longer exists,' her attorneys continued.

'Christa is a 50-year-old remorseful woman who understands her actions, receives proper treatment for mental illness and provides for and guides fellow incarcerated women.'

With Governor Lee's decision not to grant clemency, the lawyers said: 'The state of Tennessee is ignoring what both science and our legal system have decided: an 18-year-old brain is not an adult brain, and 18 is too young to face execution.'

'We will continue to support Christa through every remaining avenue and advocate for a system that is transparent for the people of Tennessee,' they vowed.

Assistant federal defender Stephen Ferrell has previously claimed in court documents that Pike was sexually abused starting from when she was a toddler and that she was raped at ages 11 and 17. 

He said Pike's lawyers at the penalty phase of her trial did not present the jury with what he claimed was critical information about her past and failed to argue that her age should be taken into consideration.

Pike was later diagnosed with bipolar disorder and post-traumatic stress disorder.

Her attorneys further claimed in her clemency petition that Pike's untreated mental illness and background made her unable to 'put the brakes on.' She had told police that she initially only wanted to fight Slemmer but ended up killing her in a frenzied attack.

'I was a mentally ill 18-year-old kid. It took me numerous years to even realize the gravity of what I'd done. Even more to accept how many lives I affected. I took the life of someone's child, sister, friend. It sickens me now to think I had the ability to commit such a crime,' Pike said in a statement included in her clemency petition.

Ferrell further argued that more is known today about adolescent brain development and that Pike's death sentence is an outlier. 

He noted that Pike's boyfriend, Tadaryl Shipp, who was 17 at the time, was sentenced to life with the possibility of parole because of his age. He was denied parole last year. A third teenager admitted to being an accessory and received probation.

As she now faces death, Pike said she feels a 'kinship' with Lindsay Clancy, whose mental health took center stage when a Massachusetts judge declared a mistrial earlier this month.

The mother had faced a lifetime behind bars for killing her children Cora, five, Dawson, three, and eight-month-old Callan. Clancy did not deny she strangled the children, but argued she should be found not guilty of murder by reason of insanity. 

'We are both females who got into trouble because of uniquely female issues,' Pike told The Times. 

'One thing [that] is different, however, is that times have changed a lot on awareness of women's issues since I was put on trial.'

She added that she is 'pleased' Clancy is 'getting the help she needs,' arguing: 'There are so many women who don't get the help they need: me and others.'

When she was then asked whether she believed jurors would have been more sympathetic to her case if she had been tried today, Pike replied that she believes she would be 'because science about brain development has evolved.' 

But Slemmer's mother, May Martinez, noted that her daughter was also a teenager when she was murdered – and never got a chance to grow up.

'Every time I think about it, I think about Colleen feeling that pain and trying to get up and run,' Martinez said.

Martinez said her daughter volunteered with the Special Olympics, loved roller skating and wanted to pursue a career in computers.

'She was easygoing. She was a computer geek to begin with. She and my husband would build and tear apart the computers constantly,' Martinez said. 'She trusted everybody, and that was her downfall.'

She said her daughter called her from Job Corps on the night of the murder, but the call was dropping because of bad reception. When Martinez called back, her daughter had already gone out.

'Not a day goes by, or a minute goes by that I do not think about Colleen. Holidays are the worst. Colleen's birthday was last week. She would have been 51,' Martinez said.

Pike is now scheduled to be executed at 10am Wednesday at the Riverbend Maximum Security Institution.