One Nisa Members' Association (NMA) board member said that he hoped Nisa-Today's would not push the merger deal any further.
He claimed: "If they do force a vote, it is more than likely the result will be seen as a vote of no confidence in the management."
Senior members of the NMA are due to meet this week in the East Midlands to discuss the deal with some of the leading wholesalers in the Today's group. The meeting will also be used to discuss the NMA's next action plan.
Meanwhile, Nisa-Today's is still carrying out the due diligence surrounding the details of the merger. A spokeswoman for the group said that it would be drawing up a newsletter for members which would include as much of the detail of the deal as possible. She added that this was likely to be sent out in early August.
A meeting of the Nisa-Today's Holdings Board is to be held in the next two weeks.