Amii has employed a PMI specialist to personally call PMI brokers and invite them to the annual conference.
According to Debbie Kleiner-Gaines, managing director of Best Health Business, the body was seeking much needed attendance from the larger players in the market.
She said: "It is not the bosses of the large broker firms we need to make contact with, but the actual brokers inside the firms.
"We are trying to make Amii more high profile and want to be taken more seriously. We need to bigger firm attendance to widen the debate at the conference."
She added during the ring-round, the one-man bands seemed chained to their desks and reluctant to leave the office for the day-long event.
Kleiner-Gaines said: "We noticed when making the calls to brokers, the one-man bands are definitely more concerned this year than ever before. There is definitely a sense of panic."