Opposition backed Presidential candidate PA Sangma will file his nomination on Thursday, the day when UPA nominee Pranab Mukherjee will also submit his papers.
Mr Sangma's office said that the 64-year-old former Lok Sabha Speaker will file his nomination papers on June 28. He is likely to be accompanied by senior BJP leaders, Janata Party President Subramanian Swamy, senior MPs from AIADMK and BJD, among others.
The tribal Christian leader, who recently quit the Nationalist Congress Party to enter the fray, met West Bengal Chief Minister Mamata Banerjee on Tuesday to solicit TMC support. However, the TMC is non-committal on the issue and there are indications that it may abstain.
NDA allies JD(U) and Shiv Sena have decided to support Pranab Mukherjee.
Mr Sangma, who is likely to lose the polls as the numbers are stacked heavily in favour of Mr Mukherjee, is making an all-out effort to improve his chances. He has even talked about the possibility of a miraculous outcome and appealed to MPs and MLAs for a conscience vote.
Mr Mukherjee came under attack from Mr Sangma on Monday when the latter held him responsible for the present economic problems in the country.