The charge was made by Congress leaders at the first meeting of the high-level state coordination committee held recently to drive home the point that the party led by Sharad Pawar has much to do to bridge the deficit.
Congress sources said the trust deficit is becoming a key issue in the party in Mumbai as party members in overwhelming numbers are expressing their opposition to any truck with the NCP in the 2007 civic elections.
Calls by senior NCP leader and state Minister Chaggan Bhujbal that the Congress and NCP should jointly fight the polls to oust the Shiv Sena-BJP combine from power in the country's economic capital have had little impact.
This is despite the NCP suggesting that it would be foolhardy to assume that Shiv Sena is "dead" in view of recent bickering and internal turmoil, and former chief minister Narayan Rane joining the Congress, while Sena chief Bal Thackeray's nephew Raj floating a parallel outfit.
The refrain in the state unit of Congress is that the NCP has often "ditched" it, whether in assembly polls or the Rajya Sabha elections earlier in 2006, when Pawar sided with BJP-Shiv Sena to ensure the victory of his industrialist friend Rahul Bajaj, who contested as an independent.
Congress leaders say they want to avoid a division of secular votes in the key polls, which will be an acid test for the Shiv Sena, whose rise in the state was phenomenal since it captured the 227-member Mumbai Municipal Corporation over a decade ago.
They, however, say an alliance for this purpose could take shape only if the NCP adopted a practical approach and refrained from making exorbitant demands.
The ideal formula for seat-sharing, according to Congress leaders, would be that it and the NCP contest seats won by them in the last civic polls as well as those where they emerged second.
If this formula is accepted, the Congress could contest 158 seats, as it won 70 seats and was number two in 88 seats.
As against this, NCP will have to be content with a mere 44 seats, including 11 it won and 33 in which it was second.
The Congress, in such an eventuality, is ready to accommodate smaller allies like the RPI to forge a formidable secular alliance that could easily shake off the Shiv Sena-BJP challenge in the civic polls.
Besides, the problems faced by the saffron partners in recent days has been a matter of jubiliation in the Congress camp, as the BJP is seeking to find its place in the sun and wanting a level playing field in the changed scenario in Maharashtra.
In an indication that the battle has started for political supremacy between itself and the NCP, the Congress has announced that it is going it alone in the local body polls and not in an alliance with the NCP, but it has not taken a decision as regards Mumbai.