A consortium of cable service providers is continuing the fight against the FCC’s embattled set-top box proposal, which would open up competition in the industry by allowing licensing agreements for new devices to stream cable TV.

In a filing made to the agency on Tuesday, service giants Comcast cmcsa and AT&T t argued that the plan would “have the effect of chilling innovation” when it comes to developing new paid programming solutions, Bloomberg reported. The filing was made by the National Cable & Telecommunications Association.

See also: TV Industry Gains Upper Hand In Set-Top Box Fight

The “unlock the box” plan has emerged as a consumer protection issue in recent months, as viewers currently have to fork out an average of $231 per year just to rent their cable boxes, propping up an industry that generates an estimated $20 billion a year, according to the FCC.

As Fortune’s Mathew Ingram reported back in February:

In a recent public statement about the move, FCC chairman Tom Wheeler—who happens to be a former head of the National Cable & Telecommunications Association—said that for too long, the set-top box has been a boon for cable and satellite companies but a bane for users. The companies selling them have made billions a year doing so, Wheeler said, but users have been locked into a captive and largely unfriendly environment in order to get service.

See also: Hate Your Dumb Cable Box? The FCC Says It’s on Your Side

The original plan reportedly would have made service providers hand over access to their programming to all set top box makers, which received an unsurprising amount of pushback from cable companies. Now, the FCC is trying to come up with a workable solution that could potentially lead to a new copyright licensing office being set up within the agency, Forbes reported.

The proposal is still being finalized and could be voted on later this month, on Sept. 29, according to Bloomberg.