The move, which could see Alpine compete with Mercedes engines as a 'customer team' from 2026, was announced on Monday after months of speculation and staff resistance.
The statement said the staff "regret and deplore the decision to stop the F1 engine in 2026" and claimed "no serious study has been carried out to assess the impact on future (car) sales and the prestige of the brand".
Alpine, struggling on the F1 track, is Renault's premium sportscar brand and is moving towards an all-electric future, with Viry-Chatillon to be transformed into a Hypertech engineering centre.
Formula One enters a new engine era with a major technical change in 2026.
While the plans for Viry include an 'F1 monitoring unit', the employee statement said the proposed staffing and budget seemed too low "and calls into question the potential return of Alpine as an engine supplier in the long term".
It spoke also of a loss of confidence in management and warned that there was a "major risk to the departure of critical skills".
The decision will leave Ferrari, Mercedes, Honda, Red Bull and Audi as Formula One's engine providers from 2026.
Renault were Formula One champions in 2005-06 with their works outfit and have a long history in the sport, powering teams to 12 constructors' titles - more than any manufacturer other than Ferrari.