In an exclusive interview with LSM, Pavilion head Elina Vikmane said those who had contributed their time and effort to the project felt "used" and described the conduct of the Economics Ministry under minister Dana Reizniece-Ozola in particular as "disgusting".
At a hastily-convened press conference, Vikmane and fellow project head Girts Majors lambasted a breakdown in communcation with the ministry, which is in over-all charge of the project.
"We had no warning that just a few months before the Expo, the climate would change completely," Majors said.
The pair also attempted to rebut press questions suggesting spending on the project was out of control with large amounts paid for relatively trivial items such as special Facebook and Instagram accounts.
Majors pointed to northern neighbor Estonia as an example of how such projects should be approached and warned that Latvia's international reputation as a "civilized and European country" would suffer if Latvia does not participate in the Expo.
The organizing body later issued a letter hinting at legal action for redress against "reputational damage" they could suffer by being associated with what looks increasingly like a doomed project.
"We are willing to publicly and in detail to explain each of the Expo 2015 costs. Today, however, we can only rebut those items that were expressed in public," the letter said, citing confidentiality clauses in agreements with the Economics Ministry.
"In view of the situation, we call on the Economics Ministry to grant permission for us to explain in detail," it added.
"EXPO 2015 has not presented a bill for a social media campaign on Instagram of €34,487... At the same time we want to stress that a social media campaign on the Instagram social networking platform base was planned as an ambitious way to involve Latvian society and the Latvian diaspora abroad."
€52,000 had been spent on specially commissioned music and films, they confirmed.
The EXPO 2015 partnership was ready to "publicly explain all cost items" but we must have permission from the client - the Economics Ministry - to do so, the statement said, concluding:
Currently, the Expo 2015 creative team is puzzled by the situation and we are not sure whether the creative people be willing to continue to cooperate, even if the government will decide to take part in an exhibition in Milan.