(CNN) - Sen. Marco Rubio appeared to take a jab at Sen. Rand Paul on Wednesday, saying candidates shouldn't run for the presidency while trying to hold onto their Senate seat.
"I think by and large, when you choose to do something as big as that, you’ve really got to be focused on that and not have an exit strategy,” the Florida Republican said on the Hugh Hewitt radio show.
Both lawmakers are considering presidential bids for 2016, when they’re also up for re-election to their Senate seats.
Rubio said Florida law prohibits candidates from being on the ballot for two different offices, a rule he described as "the right law."
Kentucky has a similar rule, but allies of Paul in the state’s GOP-controlled Senate passed a bill that would allow a candidate to simultaneously seek more than one office.
The legislation was introduced by state Senate Majority Leader Damon Thayer, who told CNN last month he hopes Paul runs for President.
The bill, however, has not been taken up in the Democratic-controlled House.
Proponents of the legislation say the bill is simply trying to clear up language of the current law, which Thayer said is meant to apply only to state-level offices, not federal offices such as the presidency, the Senate or the House.
Doug Stafford, a political adviser for Paul, said last month, "We are not seeking to change the law, but rather to clarify that the Kentucky statute does not apply to federal elections."
Rubio was asked Wednesday if he would be in favor of a rule that would allow a candidate to seek the presidency but switch back to the Senate if the bid was unsuccessful.
"I haven't even thought that far ahead," Rubio said, before going on to make his comment disparaging exit strategies.
A spokesman for Paul declined to comment on Rubio’s remarks.
Running for dual offices isn’t unprecedented.
Wisconsin Rep. Paul Ryan ran for re-election to his seat in 2012 while serving as the GOP vice presidential nominee on Mitt Romney's ticket. Then-Sen. Joe Biden also ran for re-election in Delaware while simultaneously serving as Barack Obama's running mate in 2008.
In 2000, Joe Lieberman was reelected to his Senate seat in Connecticut while losing his bid for the vice presidency when he and Vice President Al Gore, the Democratic presidential nominee, lost the election to George W. Bush and Dick Cheney.
CNN's Ashley Killough, Steve Brusk, and Alan Silverleib contributed to this report.