Republican presidential candidate Mitt Romney is raising money from his search for a vice presidential running, offering supporters a chance to meet his eventual pick in exchange for donations. 

In an email titled “My VP,” and sent to supporters Saturday, Romney said there are "many incredible men and women who I would be lucky to have as a running mate." He said the unidentified vice-presidential selection would form "America's Comeback Team" with him.

The former Massachusetts governor invited supporters to donate at least $3 by midnight for a chance to win the contest and “meet him or her on the campaign trail with me.” 

It's the second fundraising ask from the campaign this week tied to their running mate search. 

Romney’s campaign announced Thursday they would select his running mate before the Republican National Convention, which will be held the last week of August. In their email to supporters, the campaign said a donor would win the chance to meet Romney and his VP.

Romney has declined to say much about his vice-presidential search in both media appearances and campaign speeches, but his silence has not stop speculation from mounting about various candidates. 

Ohio Sen. Rob PortmanRobert (Rob) Jones PortmanWeek ahead in tech: Debate over online sex trafficking bill heats up 'Hillbilly Elegy' author won't run for Senate Brown, Portman urge Trump administration to move quickly on a steel decision MORE (R) and former Minnesota Gov. Tim Pawlenty have widely been thought to be near the top of Romney's short list, and a recent report about former Secretary of State Condoleezza Rice has raised the possibility of Romney tapping the former Bush administration official. 

Romney's campaign has acknowledged vetting Florida Sen. Marco RubioMarco Antonio RubioOvernight Defense: Senate passes 0B defense bill | 3,000 US troops heading to Afghanistan | Two more Navy officials fired over ship collisions Senate passes 0B defense bill Trump bets base will stick with him on immigration MORE (R), who has long been thought to be a 2012 vice-presidential possibility, in an effort to push back on reports the freshman senator was not being seriously considered.   

Many Republican lawmakers have pushed for Romney to announce his selection well ahead of the party’s nominating convention in Tampa, Fla., believing it would give him an added week of favorable coverage and help him raise funds.

Romney has frequently invited possible running mate selections on the campaign trail with him.