McLaren-Honda query engine development ruling for 2015
McLaren and new engine partner Honda have queried a ruling that prevents them from improving their engine during the 2015 season but allows their rivals to do so.
A senior F1 source said Honda was "annoyed" by the development.
It follows the discovery of a loophole and subsequent clarification of the rules by the FIA, the governing body.
McLaren-Honda have been in contact with the FIA about the issue but said it would not comment further for now.
The situation has arisen because of a lack of clarity in the rules concerning permitted engine developments.
The intention was to freeze in-season development, to keep costs down.
Renault and Ferrari had wanted to end the ban in an attempt to close the gap on Mercedes, which had the dominant power-unit in 2014.
Honda has been told by the FIA it must submit its definitive 2015 engine designs by 28 February, whereas Renault, Ferrari and Mercedes can stagger improvements over the season if required.
Because Honda's new engine is racing for the first time 2015, the FIA believes it is "fair and equitable" that Honda complies with the same restrictions as its rivals last year.
Honda feels the ruling puts them at a disadvantage, and will meet the FIA next week to discuss the situation.
A senior figure from one of Honda's rivals said the changes "won't make that much difference".
Honda, which has returned to F1 this season following an absence of six years, has the option of lodging a protest against Ferrari, who discovered the loophole that has led to the change in interpretation of the rules by the FIA.
Renault, Ferrari and Mercedes have so far not responded to requests to comment from BBC Sport.
The season starts with the Australian Grand Prix in Melbourne on 15 March.
|Engine development - the detail|
|Complex turbo hybrid engines were introduced in 2014|
|Development rules follow a formula that defines 92% of the engine as being open to development from the first season of the design to the second|
|From this, manufacturers choose a maximum of 48% they can develop|
|This 48% is split into 32 'tokens', assigned to parts of the engine depending on their influence on performance|
|Following the latest FIA rule clarification, manufacturers in their second season are now able to implement their 32 development tokens over the course of the year, rather than having to do so before the season starts|