Talks between the Congress and the DMK appear to have made some headway though there was no official confirmation from either side on this.
Off the record, Congress leaders said they were "hopeful that the matter can be resolved soon" through "back channel talks".
Finance minister Pranab Mukherjee had called DMK chief MK Karunanidhi early on Monday morning asking him to reconsider his decision to pull out his party's unconditional support to the UPA, said the DMK's parliamentary party leader T R Baalu.
No Congress leader, however, was willing to comment on this.
Later in Parliament, Mukherjee held the met political secretary to the Congress chief, Ahmed Patel, home minister P Chidambaram and general secretary in-charge for Tamil Nadu Ghulam Nabi Azad, following which DMK's Dayanidhi Maran was also invited to join them.
Political observers say there are indications of a breakthrough in talks as DMK ministers had earlier said they would be resigning at 11am on Monday. That time has now been shifted to 6.30pm.
The six ministers, including MK Alagiri, will meet the Prime Minister in Delhi and hand over their resignation.
DMK leader TR Baalu said party ministers would reach Delhi on Monday and submit their resignations though Congress sources said they have no official communication from the DMK on this.
The DMK has two cabinet ministers and four ministers of state at the centre.
A day after the Dravida Munnettra Kazhagam (DMK) announced its withdrawal from the Congress-led United Progressive Alliance (UPA) government at the Centre, the rift between the two widened as both parties hardened their positions against a rapprochement on Sunday.
The DMK also called off its alliance with the Congress in Tamil Nadu, which goes to polls on April 13. The parties have been allies since 2004 and DMK has 18 members in Lok Sabha.
The DMK has been running a minority government in Tamil Nadu since 2006 with the outside support of the Congress.
While the DMK maintained that if the Congress scales down its demand for seats - the party is demanding 63 seats of its choice - a reunion is possible.
But the Congress ruled out such a possibility.