Responding to a letter written by Modi to Prime Minister Manmohan Singh, the PMO dubbed as "unsubstantiated allegations" its contents about discussions with Pakistan on the Sir Creek issue.
"The contents of the letter and the timing of its release to the public, even before it was formally received in this (PMO) office, raise questions about the motives behind its issue," the PMO said in a statement.
"The writing and release of this baseless letter by the Chief Minister of Gujarat in his "personal" capacity, a day before elections in the state, is mischievous," the PMO said.
It said the allegation in the letter that Sir Creek is "about to be given to Pakistan is untrue. Therefore, the other conclusions drawn by Shri Modi from this alleged fact are also not real."
Taking a dig at the Chief Minister, the PMO said, "it also seems that Shri Modi has written his letter without making any efforts to ascertain the facts from the Government of India."
The PMO reminded Modi that the discussions on Sir Creek have been carried out by successive Governments of India since the dialogue process began in 1998, and continued after the then Prime Minister Atal Behari Vajpayee's visit to Lahore in 1999.
Modi expressed apprehensions just ahead of Pakistan Interior Minister Rehman Malik will be travelling here from December 14 to discuss a range of bilateral issues.
Modi, in his letter to the Prime Minister, had said Sir Creek, a marshy land in Gujarat, should "not be handed over to Pakistan" and talks on this issue should be stopped.
