GOP presidential rivals Ted Cruz and Marco Rubio are trading shots over abortion ahead of a critical Saturday night debate in South Carolina.

{mosads}The fight began with a shot by Sen. Cruz (R-Texas), who told an evangelical audience in the state Friday that Rubio voted in favor of a spending bill that included money for Planned Parenthood.

Rubio has fought back with a series of tweets and statements, arguing Cruz’s insinuation that he is weak in opposing abortion is ridiculous.

“Marco Rubio has been and always will be a staunch defender for life,” former senator Rick Santorum, a Rubio backer who ended his own presidential bid last week, said in a statement pushed by the Rubio campaign. “For Ted Cruz to suggest otherwise is a disservice to the pro-life cause.”

“We need a leader like Marco who can unite conservatives in the fight for life, not people like Ted Cruz who choose to weaken the pro-life movement for political gain,” he said.

The Cruz campaign maintained that Rubio did not stand against abortion when it mattered most.

“Marco Rubio should have stood with conservatives to use Congress’s power of the purse to defund Planned Parenthood in the spending bill last September,” Cruz spokesman Brian Phillips said in a statement to The Hill.

“Instead, Rubio didn’t even show up for the vote,” he added. “The one vote he did show up for was a ‘show vote’ that everyone knew wouldn’t pass.”

Cruz campaign communications director Rick Tyler also on Saturday said in a tweet that Rubio is “not with us.”

When is mattered, Rubio voted for the CR to fund Obamacare and Planned Parenthood.https://t.co/RUP7nv1oYM #CruzCrew pic.twitter.com/auGmBAaaxp

— Rick Tyler (@rickwtyler) February 13, 2016

The fight is important in South Carolina, where abortion is a big issue for anyone hoping to do well in the state’s Feb. 20 primary.

Cruz is polling in second place in the state behind Donald Trump, while Rubio is battling with Jeb Bush and John Kasich for third place.

The Texas senator’s attack is rooted in a 2014 vote Rubio made for a bill that kept the government funded. Cruz voted against the legislation.

Rubio earlier in the campaign said he would oppose abortion in cases of rape and incest, and his campaign did not take Cruz’s attack lying down.

Rubio operative Joe Pounder hit back, pointing out that Sens. Elizabeth Warren (D-Mass.) and Bernie Sanders (I-Vt.) also voted against the continuing resolution.

.@tedcruz cites vote where he sided with @SenWarren and @BernieSanders. Didn’t know we had two socialists running. https://t.co/nMuDm1k2gW

— Joe Pounder (@PounderFile) February 13, 2016

And Rubio campaign spokesman Jahan Wilcox said the attack is evidence that Cruz will “say or do anything to win an election.”

“Marco Rubio has always voted with [Sens.] Tim Scott and Joni Ernst to defund Planned Parenthood and anythng to the contrary is false,” Wilcox said in a statement to The Hill.

Later, a string of political allies offered messages of support for Rubio, and criticism for Cruz.

Former Louisiana govenror Bobby Jindal, who also recently suspended his presidential campaign, said Cruz “lied about Marco Rubio.”

“Instead of working to unite conservatives and defund Planned Parenthood, Cruz is using the issue as a political weapon,” Jindal said in a statement released by the Rubio campaign.

“I expect Democrats like Hillary Clinton to falsely attack conservatives over the sanctity of life, but I expected more from Ted Cruz,” he added.

Rep. Trey Gowdy (R-S.C.), an influential House Republican who is backing Rubio’s presidential bid also said he was “bitterly disappointed” in Cruz’s attack.

“Marco is passionately committed to the pro-life cause and has repeatedly voted to defend Planned Parenthood,” Gowdy said in a statement released by the campaign. “Marco’s unwavering defense of life is one of the reasons I so enthusiastically support him.”

“I am bitterly disappointed Ted Cruz would try to intentionally mislead my fellow South Carolinians,” he added.

The National Right to Life (NRLC), an anti-abortion-rights group, also said Cruz and Rubio have identical voting patterns on issues pertinent to ending abortion and condemned Cruz for insinuating otherwise.

“Marco Rubio voted to defund Planned Parenthood before Ted Cruz ever got to the U.S. Senate,” NRLC President Carol Tobias said in a statement to The Hill, pointing to an April 2011 vote.

“Since Ted Cruz joined the U.S. Senate, both he and Sen. Rubio have voted the same on every roll call that National Right to Life regards as pertinent to defunding Planned Parenthood,” she added. 

Prominent conservative evangelical blogger Erick Erickson also tweeted in support of Rubio.

Marco Rubio is pro-life. If you think otherwise, you are wrong.

— Erick Erickson (@EWErickson) February 13, 2016