"As always, there are the usual 'nominees' and some newcomers, some famous and some unknowns, hailing from the four corners of the world," the head of the Nobel Institute, Geir Lundestad, told AFP.
With 188 individuals and 43 organisations, the number of candidates comes close to last year's record of 241, when the prestigious award went to Liberian President Ellen Johnson Sirleaf, Liberian activist Leymah Gbowee, and Yemeni "Arab Spring" activist Tawakkol Karman.
Thousands of people are eligible to submit nominations, including members of parliaments and governments worldwide, university professors, past laureates and members of several international institutes, who had until February 1st to propose candidates.
The Nobel Institute keeps the names of nominees secret for 50 years, but those who are entitled to nominate are allowed to reveal the name of the person or organisation they have proposed.
Among the people known to have been nominated for this year's prize are former US president Bill Clinton, ex-German chancellor Helmut Kohl who led his country's reunification process, and Ukraine's ex-premier and now jailed opposition leader Yulia Tymoshenko.
Also on the list is jailed US soldier Manning, who has been charged with 22 counts in a US military court for turning over a massive cache of classified US documents to anti-secrecy site WikiLeaks.
Despite its current crisis, the European Union is also among the candidates, as are Congolese doctor Denis Mukwege, Cuban dissidents Oswaldo Paya and Yoani Sanchez, and Russian rights group Memorial and its founder Svetlana Gannushkina.
Yet others include US political scientist Gene Sharp, known for his theory of non-violent resistance which inspired some of the key figures behind the Arab Spring, Tunisian President Moncef Marzouki who was brought to power in 2011 by the revolution in his country, and television news channel Al-Jazeera.
The winner or winners will be announced in October.
But the prize, which every year generates a media frenzy and occasionally sparks controversy, has recently been criticised for not following the wishes of prize creator Alfred Nobel.
Swedish authorities tasked with ensuring that foundations created by wills follow their statutes -- including the Nobel Foundation -- are investigating whether the Norwegian Nobel Committee is correctly carrying out the task assigned to it by Alfred Nobel in his 1895 will.
The Swedish inquiry follows repeated criticism from Norwegian lawyer Fredrik Heffermehl, author of the book "The Nobel Peace Prize: What Nobel Really Wanted".
Heffermehl claims the five-member prize committee has gone astray by honouring people such as Chinese dissident Liu Xiaobo in 2010, environmentalists Al Gore and the IPCC in 2007 and humanitarian activists such as Mother Teresa in 1979.
In his last will and testament, Nobel stipulated that the Peace Prize should go to the person or organisation that "shall have done the most or the best work for fraternity between nations, for the abolition or reduction of standing armies and for the holding and promotion of peace congresses."
"We are eager for this debate to end," Lundestad said on Monday.
"The debate has been going on for years and nothing has really come of it," he said.
"I'm eager for the debate to start. For four years I've neither seen nor heard a single response to my questions," he retorted.
"What cause and which people did Nobel have in mind when he spoke of 'champions of peace'? The answer is so easy and so clear that if Lundestad and his committee accepted it, their only reaction would be to resign immediately," he said in an email to AFP.