For days, Mitt Romney has been seeking to use Newt Gingrich’s past against him.

Former House speaker Newt Gingrich (R-Ga.). (AP Photo/Jim Cole)

In a new Spanish-language radio ad airing in South Florida, Gingrich’s campaign is reviving a 2007 campaign-trail gaffe in which the former Massachusetts governor mistakenly attributed to a free Cuba a trademark slogan of Fidel Castro.

The phrase – “Patria o muerte! Venceremos!” – is Castro’s signature sign-off. In English it means, “Homeland or death! We shall overcome!”

During his 2008 presidential campaign, Romney used the slogan in a speech before a Cuban-American crowd in Miami, accusing Venezuela’s Hugo Chavez of trying to appropriate the “inspiring phrase.”

As Rick Perry might put it: Oops.

In its minute-long radio ad, news of which was first reported by the Miami Herald, Gingrich’s camp opens with a clip of the slogan. A narrator then intones in Spanish:

“Amazingly, this phrase was also used by Mitt Romney.”

The spot goes on to allege that Romney is “the most anti-immigrant candidate” and charges that he is “a liberal” in the same style (and from the same state) as the late Sen. Ted Kennedy (D-Mass.).

It also states that Gingrich fought alongside “Ileana and Lincoln” – that’s Rep. Ileana Ros-Lehtinen (R-Fla.) and former congressman Lincoln Diaz-Balart (R-Fla.) – to pass the Helms-Burton Act, the 1996 measure aimed at strengthening the embargo against Cuba.

Not mentioned in the Gingrich ad? Ros-Lehtinen and Diaz-Balart have endorsed Romney in the 2012 race, and they appear in a Spanish-language Romney campaign TV ad currently airing in the Sunshine State.

The Gingrich spot is a sign that the former House speaker’s camp is aiming to stay in the race beyond Saturday’s primary in South Carolina, where the candidate has seen a surge of support in recent days. Florida holds its nominating contest on Jan. 31.

But in Florida, Gingrich will likely face the same problem as he has elsewhere when it comes to his effort to unseat Romney as the GOP frontrunner: the former Massachusetts governor has a vast campaign warchest at his disposal.

Romney spokesman Alberto Martinez’s response to the ad, via the Miami Herald:

“This ad is false and full of ridiculous claims. Mario Diaz-Balart, Ileana Ros-Lehtinen and Lincoln Diaz-Balart all stand with Mitt Romney because he has laid out a clear vision for spreading democracy in our hemisphere. By attacking anyone who supports common-sense border security and immigration reforms as ‘anti-immigrant,’ Newt Gingrich is once again reading from Barack Obama’s liberal talking points.”

Below is the Spanish transcript of the ad, followed by an English translation. Audio of the ad, courtesy of the Miami Herald, is here.

Spanish transcript:

“¡Patria o muerte! ¡Venceremos!”

“Asombrosamente, esta frase también fue usada por Mitt Romney.”

“Mitt Romney es un liberal del estado y al estilo de Kennedy.”

“Él es el candidato más anti-inmigrante.”

“Mitt Romney tendrá la fama. Pero no tiene la sustancia para ser nuestro presidente.”

“En contraste, Newt Gingrich es un candidato que se ha comprometido con el pueblo hispano. Un republicano al estilo de Ronald Reagan, con experiencia.”

“A diferencia de Romney, que anda usando frases Castristas, Newt Gingrich luchó en contra del régimen, junto a Ileana y Lincoln, para aprobar la ley Helms-Burton. Apoyó la creación de Radio y Televisión Martí, y está a favor de encausar a los hermanos Castro por el derribo de las avionetas Hermanos al Rescate.”

“Newt Gingrich ha dado su palabra a la comunidad cubana por escrito, y no nos defraudará.”

“Treinta y uno de enero, vote por Newt Gingrich, marcando el doce en su boleta.”

“Soy Newt Gingrich, y apruebo este mensaje.”

English translation:

“Homeland or death! We shall overcome!”

“Amazingly, this phrase was also used by Mitt Romney.”

“Mitt Romney is a liberal in the same style, and from the same state, as Kennedy.”

“He’s the most anti-immigrant candidate.”

“Mitt Romney may have the fame -- but he doesn’t have the substance to be our president.”

“By contrast, Newt Gingrich is a candidate who has committed himself to the Hispanic people -- an experienced Ronald-Reagan Republican.”

“Unlike Romney, who runs around using Castroist phrases, Newt Gingrich fought against the regime together with Ileana and Lincoln to pass the Helms-Burton Act. He supported the creation of Radio and TV Martí. And he supports prosecuting the Castro brothers for the downing of the Brothers to the Rescue planes.”

“Newt Gingrich has given his word in writing to the Cuban community, and he won’t let us down.”

“On January 31st, vote for Newt Gingrich by marking No. 12 on your ballot.”

“I’m Newt Gingrich and I approve this message.”