Donald Trump's Vice Presidential short list includes Chris Christie and Newt Gingrich

The New York tycoon is set to formally announce his running mate at the party's convention in Cleveland

Donald Trump takes to the stage last night at a campaign rally in Bangor, Maine (Reuters)

Former House Speaker Newt Gingrich and New Jersey Governor Chris Christie are among the front runners currently being vetted by Donald Trump as he looks to select a vice presidential candidate.

Mr Trump is set to announce his choice at the Republican National Convention later this month in Cleveland, and he hopes the news will give him a jump in the polls.

The New York tycoon has previously said he whittled down a shortlist to “a very good list of five or six people.” Yet reports suggest he has only begun the formal vetting procedure in the last few days.

<em>Darren McCollester/Getty</em>

There is intense interest in who the 70-year-old will select as his running mate. The Associated Press said that his pick could be crucial to easing the concerns of Republicans who worry about his lack of political experience, as well as his temperament.

At the same time, he could choose someone who could help him win one of the battleground states in November. Earlier reports reports suggested that he was also looking as having a woman on the Republican ticket.

A number of potential picks have ruled themselves out. Mr Trump may have liked to reach out to Senator Marco Rubio, who is young, would help him with both the Hispanic community and Florida, and who is liked by much of the Republican establishment.

But Mr Rubio, who clashed with Mr Trump in the final Republican debates and whom the New Yorker mocked as “Little Marco”, has said he does not want to be considered for the position.

“I have never sought, will not seek and do not want to be considered for vice president,” Mr Rubio wrote on Facebook.

(Getty (Getty)

The AP said that Mr Gingrich and Mr Christie, who both received vetting paperwork in the last 24 hours, emerged as prominent allies of Mr Trump in recent months, even as the presumptive nominee faced deep and sustained skepticism from many Republican leaders.

It was Mr Christie’s aggressive questioning of Mr Rubio and his faltering response during a debate in New Hampshire, that many believe sapped the Florida’s senator’s then soaring momentum.

Mr Trump’s relationship with other would-be running mates was badly strained in the bruising Republican primary season, leaving him with a small pool of willing and qualified candidates. Mr Trump has since criticised those have failed to endorse him, saying they got “beaten up” during the primary.

Mr Trump on Thursday acknowledged Mr Christie, who has been mocked by many for his sudden change of heart over Mr Trump’s candidacy, was under consideration.

“I’m certainly looking at him and I always will. Whether it’s for that or something else,” Mr Trump told conservative radio host Howie Carr. He later described Indiana Governor Mike Pence as “somebody we respect a lot.”

Mr Pence told Indiana reporters on Thursday he hasn’t spoken with Mr Trump in several weeks and referred questions to the Trump campaign, which declined to comment further on the vice presidential search.

Mr Trump said last month, and has repeated in the weeks since, that he preferred someone with political experience to help him guide his agenda through Washington.

“I think that’s good for a number of reasons. No 1, if you win, which hopefully we will. I want help with - you know, I want a hand with legislation, getting things through. And if you bring a business person - we don’t need another business person,” Mr Trump said.

Mr Christie was vetted four years ago by 2012 nominee Mitt Romney’s research team. The Christie administration’s more recent involvement in the so-called “Bridgegate” political retribution scandal could complicate his 2016 prospects.

Mr Gingrich, who ran for president in 2012, served as House speaker from 1995 to 1999. He has substantial political baggage as well, having been married three times and lived in Washington for decades.