Congress core group meeting will be held on Tuesday at interim party president Sonia Gandhi's residence over the political situation in Maharashtra.
Earlier in the day, NCP had said that it will take a decision on government formation in Maharashtra by Tuesday after holding consultations with its ally Congress.
The NCP finished on the third position in the assembly polls having won 54 seats.
"We have been called by the Governor. We have been called to form the government. As per the letter given by the Governor, we will hold discussions with Congress and see how a stable government can be provided to the state. We will get the letter today and make a final decision by tomorrow after holding discussions with our ally Congress," NCP leader Nawab Malik told the media here.
Maharashtra Governor Bhagat Singh Koshyari called NCP after meeting a delegation of Shiv Sena which had expressed its intent to form the government and sought more time to provide a letter of support. However, the Governor declined to give more time.
The BJP had emerged the single-largest party in the assembly polls followed by Shiv Sena. Both parties had contested the polls together.