The Bharatiya Janata Party (BJP) Friday anointed Modi as its prime ministerial candidate for the Lok Sabha polls.
The ex-servicemen rally will also be addressed by former army chief Gen. V.K. Singh, BJP leaders said.
They said Modi would speak on national security and matters concerning ex-servicemen, including challenges faced by them in seeking post-retirement employment.
His speech is likely to be watched for any promises he makes on issues concerning ex-servicemen and his attack on the United Progressive Alliance (UPA) government for its handling of security issues such as incursions by China, repeated ceasefire violations by Pakistan and instances of attack on Indian soldiers.
However, a day ahead of the event in Rewari, about 90 km from the national capital, Haryana Power Minister Ajay Singh Yadav targeted Modi while some unidentified people blackened posters of the BJP leader.
Yadav said Haryana did not have to take lessons from Modi's model of governance in Gujarat.
"Modi should have chosen a state that lags Gujarat. Haryana is ahead of Gujarat in key fields, including social welfare schemes, especially for defence personnel and ex-servicemen," Yadav said.
"Gujarat government's incentives and facilities to freedom fighters, defence personnel, ex-servicemen and their dependents pale in comparison to what the Bhupinder Singh Hooda government has done in Haryana," he added.
Dismissing Modi's rally as an "attempt to mislead people and undermine the dignity of sainiks (soldiers) and freedom fighters", Yadav advised Modi to implement Haryana's innovative schemes in Gujarat.
Meanwhile, BJP leaders said over a lakh people were expected to take part in the rally, being organised by the Haryana unit of the party and its ex-servicemen's cell. They said over 20 senior retired defence personnel would attend.
There is speculation that V.K. Singh may join BJP at the rally.
BJP spokesperson Capt Abhimanyu, convenor of the rally, Saturday said the government should have a well-defined welfare policy for defence forces.
"This will be the largest rally on issues of national security and welfare of ex-servicemen," he said.
--IANS (Posted on 14-09-2013)