Both Sauber and Force India have written to the FIA and FOM to express their belief that not enough has been done to help the smaller F1 teams on the engine front.
Team representatives Monisha Kaltenborn and Bob Fernley held further discussions on the matter with Bernie Ecclestone and FIA President Jean Todt last weekend in Barcelona.
It is unknown however exactly what transpired from the meetings as Force India's Fernley, while acknowledging a missive had been sent to both parties, refused to elaborate on the letter's exact content.
"A letter was sent to the FIA and the commercial rights holder, putting our position to them,” Fernley explained to Motorsport.com.
"I'm not going to deny that we sent it, but I'm not going to comment on it either."
As a reminder, Sauber and Force India filed a formal complaint in September 2015 with the European Competition Commission, addressing what they see as unfair and 'unlawful' practices in Formula 1's governance and distribution of revenues.
"The EU have slightly restructured because of the pressures that the competition department are under," Fernley explained.
"The sports complaints or inquiries have been put into one division. Because it's been moved, it has to go through the process again - in other words, people have to get up to speed and so on. Once they are ready, they will advise us.
"From our point of view, we can only work with the process that's available to us, and obviously we'd like to see the EU investigating, because clearly we need an independent body that has the power to make changes if necessary, and should they feel our complaint reasonable.
Bernie Ecclestone dismissed the complaint at the time, which also labeled F1 as a 'cartel', playing down its significance to the point where he hoped the competition authorities would indeed take the time to deal with it.
"“In all fairness, Bernie has dealt with this in a professional manner," Fernley concluded.
"He knows we're not happy and he respects our position, and I think it's a case now of it just going through the process."
LIVE: Barcelona post-race test - Day 2
Spanish Grand Prix - Quotes of the weekend
DRIVER RATINGS: Spanish Grand Prix
Keep up to date with all the F1 news via Facebook and Twitter