Sen. Rand Paul (R-Ky.) – a founding member of the Senate Tea Party Caucus – said Monday it would be bad for the tea party if his father, Rep. Rand Paul (R-Texas), decides to run as a third-party presidential candidate, according to John McCormack of the The Weekly Standard.

“I’m encouraging him to try to win the Iowa primary,” said the younger Paul following an interview with a Des Moines radio station during a five city campaign swing with his father on the eve of the Iowa caucuses. “It’s kind of hard to think about leaving your party when you might be the nominee.”

However, the Kentucky senator was vague when asked if he would support his father if he launched a third-party presidential bid.

“I’ve always said I think the Tea Party movement is best and most effective within the Republican Party,” he said. “The Tea Party movement as a separate movement would divide some of the Republican vote.”

The latest Des Moines Register poll released over the weekend showed Ron Paul in second place behind former Massachusetts governor Mitt Romney, 24 to 22 percent. However, the Register’s poll revealed that Rep. Paul is viewed by likely Republican caucus-goers as the least likely to win the general election.

“I have not been publicly in favor of a third-party candidate and I have not been in favor of the Tea Party splitting off,” Sen. Paul said. “But I think people need to rethink that question when a guy’s leading the polls in Iowa – to be asking about running as a third party when we’re still talking about winning the Republican nomination.”

However, when Rand Paul was asked whether he definitely would or would not support his father as a third-party candidate, Paul again deflected the question: “Right now, we’re concentrating on winning the Republican nomination.”

Rep. Paul was the Libertarian Party’s presidential nominee in 1988, and ran for the GOP nomination in 2008. As recently as October of last year, Rep. Paul had not completely ruled out the notion.

"I have no intention of [running as a third party candidate]," Rep. Paul told CNN. "Nobody's particularly asked me to do it and they know what I'm doing and I have no plans whatsoever to do it."

McCormack also speculates that “one big factor weighing against such a decision is concern for the political future of his son, a Tea Party star in his own right and potential presidential candidate in 2016 or 2020.”