(CNN) -- Mitt Romney said Tuesday that a report that Sen. Marco Rubio was not being vetted as a possible running mate is "entirely false."
"Marco Rubio is being thoroughly vetted as part of our process," Romney said in Holland, Michigan.
An earlier ABC News report said that Rubio had not yet been asked for documents in connection with the vetting process, which presumably began approximately two months ago when Romney chose his former gubernatorial office chief of staff, Beth Myers, to lead his selection effort.
"There was a story that originated today, apparently at ABC, based on reports of supposedly outside, unnamed advisors of mine," Romney continued. "I can't imagine who such people are but I can tell you this. They know nothing about the vice presidential selection or evaluation process. There are only two people in this country who know who are being vetted and who are not, and that's Beth Myers and myself."
The story would not come from her, he said: "I know Beth well. She doesn't talk to anybody."
Rubio is a favourite of conservatives, and some might see it as a snub not to include him on a list of potential candidates. Some however note the 41-year-olds age and lack of experience having only just started his first term as Senator from Florida.
On CNN's "The Situation Room," Republican strategist Ana Navarro, a CNN contributor who was formerly national Hispanic chair for Jon Huntsman's presidential bid, said she thought he "should be vetted," and that the leak may be a result of someone who has "an axe to grind against Marco Rubio."
"Marco Rubio deserves to be taken seriously," she said. "I think it's a mistake and a surprising mistake by a campaign that has until now has shown tremendous message discipline and leak control."
Earlier Tuesday afternoon, Rubio repeatedly refused to answer questions about the selection process and whether or not he was part of it.
"I just don't talk about this process at all. I just don't discuss the process in any way," he said in an interview conducted prior to Romney's announcement. "Governor Romney is going to make a great choice."
Romney has previously declined to put any names in play -- or take them out of consideration -- making Tuesday's statement particularly notable.
Also in the Tuesday interview, Rubio suggested that the Dream Act alternative he was working on had been sidelined by President Barack Obama's Friday announcement of an immigration policy change.
"That's what I was working on," he said in an interview.
Earlier in the day his spokesman said his Senate office was "re-evaulating our plans" for such legislation. Obama announced a plan to temporarily suspend the deportations of some young immigrants who were brought to the country as children, provided they were pursuing higher education or military service and had no criminal record.
In the Fox interview, Rubio echoed other Republicans in saying that Obama's directive has "poisoned the well" to passing legislation on the issue. Political analysts have pointed out that any major legislative action is unlikely in this election year.
Rubio turned that as a criticism of Obama.
"I got elected to be a serious policy maker not some guy who does press releases in an election year," he said.
CNN's Rachel Streitfeld, Ashley Killough, and Gregory Wallace contributed to this report
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