Elections are due to be held in India next month to select a new president to replace APJ Abdul Kalam when his term of office expires, officials say.
Mr Kalam has been a popular president
The Election Commission says that a vote will have to go ahead if the ruling coalition and the opposition do not agree on a consensus candidate.
Mr Kalam, a former missile scientist, has served five years in the post.
He was known as the "people's president" for his approachability and good nature, correspondents say.
The commission said that if elections are necessary, they will take place on 19 July.
The president of India serves a mainly ceremonial role as the country's titular head of state.
But correspondents say office holder can play an important role in determining who will be prime minister in the event of a hung parliament.
The president also has the power to delay some bills before they become law.
Correspondents say that while the constitution allows a president to serve a second term, none has done so except the first incumbent, Rajendra Prasad.
According to reports, Home Minister Shivraj Patil is expected to be the candidate of the ruling Congress party.
Vice-President Bhairon Singh Shekhawat, a former leader of the Hindu nationalist Bharatiya Janata Party, is also expected to be a candidate.
The president is elected by an electoral college made up of MPs and members of state legislatures.