Former Arkansas governor Mike Huckabee (R) said Sunday that Mitt Romney should choose Sen. Marco Rubio (R-Fla.) as his running mate.

Huckabee argued in a “Fox News Sunday” roundtable that Rubio would be the strongest choice for Romney, the former Massachusetts governor and presumptive GOP presidential nominee.

Rubio, a freshman senator and rising GOP star, is often floated as among the top choices for Romney. He and Huckabee have ties back to
Sen. Marco Rubio ( R-Fla.). (Jae C. Hong - AP) the 2008 campaign, when Rubio, then Florida state House speaker, endorsed Huckabee’s presidential bid and campaigned on his behalf.

Huckabee later endorsed Rubio over then-Gov. Charlie Crist in the hotly-contested Florida Senate GOP primary in 2010. Crist, a Republican at the time, ended up leaving the GOP and running as an independent amid mounting conservative support for Rubio’s bid.

While many Republicans have touted Rubio as a top VP choice, some prominent voices in the party have argued that the Florida Republican is not yet ready for the VP slot; former Attorney General Alberto Gonzales told CNN on Saturday that he believed Rubio’s “resume does not reflect someone prepared to confront serious and dangerous issues that our country faces as president.”

As the vice-presidential speculation heats up, some have debated whether Romney should pick a running mate sooner rather than later so as to have more firepower in making the case against President Obama on the trail. Huckabee said Sunday that he believes there’s “no advantage in picking (a running mate) early,” since it would give the White House more time to make attacks on both Romney and his VP choice.

Ed Gillespie, an adviser to the Romney campaign, also appeared on “Fox News Sunday.” He told host Chris Wallace that contrary to some reports, he is not heading up the former Massachusetts governor’s running-mate search.