"We are with UPA and will remain with UPA. If there is an NDA government headed by Narendra Modi, we will sit in the opposition," party chief spokesperson D P Tripathi told PTI.
When asked about reports that the Sharad Pawar's party was cosying up to BJP, Tripathi said, "There is no question... it is not true".
Tripathi remarks came after Patel said yesterday that the country should have a "stable" government which will "decisively govern" for the next five years.
He said the people's mandate has to be respected as the country has to move forward.
Asked if his party would support NDA if it falls short of the half-way mark of 272 seats, Patel had said no conjecture should be drawn against NCP or it taking any sides.
"Call it the exit polls or the opinion polls, this is the general view that BJP will emerge as the single largest party," he had said.
"The question is how close they are able to come to the halfway mark or if they want any ally, all this will become clear on May 16. But the government should be stable. A stable and good government is good for the country," he said.
The NCP is the second largest constituent of the UPA after Congress and the two parties are sharing power in Maharashtra since 1999 few months after Pawar parted ways with Congress on the issue of foreign origin of Sonia Gandhi.
The two parties are sharing power at the Centre since May 2004.
'US will work with whoever wins the election in India'
Modi's party sells Indian voters low-cost housing dream
Modi sells Indian voters low-cost housing dream
Why Manmohan sarkaar wasn't really bekaar
8 reasons why a surprise awaits Modi down south