Contacted by AFP, a spokesman for Kensington Palace, the prince's official residence, said: "It has been decided that an official list of political leaders -- both UK and international -- is not required for Prince Harry and Markle's wedding".
Former prime minister David Cameron was invited to the 2011 wedding of Harry's brother, Prince William, who is second in line to the throne after their father, Prince Charles.
Harry's place in the line of succession makes this wedding politically less significant and the couple have instead invited youth workers and military veterans to attend the wedding, Presstv reported.
Harry is fifth in line to the throne and will soon find himself in sixth place after William's wife Kate gives birth as expected later this month.
Kensington Palace also said on Tuesday that 2,640 people would be invited on the day into the grounds of Windsor Castle, where the couple will be married in St George's Chapel on May 19.
Of those, 1,200 have been picked out by royal officials from around the country and the remainder will be members of the public, guests from charities associated with the couple.
Among the invitees is 30-year-old Philip Gillespie, a military veteran who lost his right leg in an explosion in Afghanistan and was a participant in the Invictus Games for wounded service personnel, which Harry founded.
Another is Rosie Ginday, 34, the founder of "Miss Macaroon", a charity that provides culinary training and employment opportunities for disadvantaged young people in Birmingham.
Twelve-year-old Amelia Thompson who was caught up in last year's Manchester Arena terror attack in which 23 people were killed and hundreds more injured, is also on the list.
The invitees will be able to watch the arrivals of the bride and groom and their wedding guests at the chapel and the carriage procession as it departs from the castle after the service.