French auteur cinema has been plunged into turmoil over a new collective labour agreement for the film industry. The heated debate is destroying the ties that have held together a sector that, while fragile, was always united in its desire to make films, come what may. Now grips, electricians, dressers, assistant directors, producers and cameramen alike are split into pro and anti camps, the dominant attitude being "tell me if you're for or against the agreement, and I'll tell you if I'll speak to you or insult you".

The collective labour agreement for crew in the French film industry was signed in January 2012 by most of the technicians' unions and four industry heavyweights, Gaumont, Pathé, UGC and MK2. The aim was to regulate a profession that has never been included in French labour laws, with the exception of a wage scale dating back to 1950, which is updated from time to time and serves as a guideline. However, technicians may be paid 10%, 20%, or even 50% below the pay scale depending on a film's budget, and given the shortage of adequate financing, the share of "poor" films has grown.

The opponents, including the majority of French film directors, have sounded the alarm, saying that the minimum wages stipulated in the new agreement, together with overtime and night rates for the crew, will jeopardise financially fragile films.

The agreement does provide an exception for fiction films with budgets of under €2.5m ($3.3m), but that is not enough for the opponents. In January this year they drew up an alternative proposal, approved by the CFDT union, which stipulated variable pay scales according to the film's budget. Supporters of the collective agreement claim that this will result in a two-speed film industry.

This issue has been a nightmare for minister of culture Aurélie Filippetti since her appointment in May 2012. Should the agreement now be extended to the entire industry? Supporters and opponents have lobbied her office. The socialist government certainly does not want to be accused of "killing" independent art house cinema. Last December, the leftwing film director Robert Guédiguian published an article in Le Monde in which he explained that he could never have made his first seven films if he had respected the minimum wage, and admitted to having hired people illegally.

He was applauded by some and booed by others. The lines are certainly getting blurred. How can a leftwinger like Guédiguian, who directed Marius et Jeannette, be against a labour law that protects workers? Supporters of the agreement, including the Association of Film Makers (Société des Réalisateurs de Films, SRF), which organises the directors' fortnight at the Cannes film festival, criticised "committed leftwing film-makers who behave like the worst business bosses".

A counter-attack was needed. Numerous technicians publicly asserted their support for the collective agreement, which, despite its avowed shortcomings, will provide them with a degree of security. Many of them are tired of being unable to earn a decent living from their professions, even with 15 or 20 years of experience under their belts.

'Not a bridge but a fault line' … a still from Pascale Ferran's award-winning Lady Chatterley. Photograph: PR handout

Tensions rose and in March the government finally announced that the agreement would be extended to the entire sector. In April it appointed Raphaël Hadas-Lebel, a senior member of the council of state, as mediator to defuse the situation.

In April film producer Pascale Ferran and nine others, including Agnès Jaoui, Cédric Klapisch, Robert Guédiguian and Céline Sciamma, published an appeal in the newspaper Libération "to get out of the deadlock". It suggested even more flexible proposals to those in the alternative agreement, permitting case-by-case negotiations in certain cases and below pay scale rates.

Pascale Ferran is a very socially aware director, who took the César best film award for Lady Chatterley in 2007. The following year she launched the 13 Club thinktank on financing for middle films, referring to those that are halfway between being major productions and low-budget films. "The middle is no longer a bridge but a fault line," concluded the thinktank's report. That seems particularly relevant today.

Interestingly, the major figures in art house cinema are not all against the agreement. Alain Guiraudie, who directed Stranger by the Lake, defended it when his film was launched in June. In the weekly culture magazine Télérama, he scorned the alternative proposals saying: "So the technicians' minimum wage should be pegged to the film's budget, and too bad for the 'equal work for equal pay' principle! And while we're at it, why not a specific minimum wage for companies with fewer than 50 employees?"

In June the SRF held its annual meeting to renew its board of directors. The growing number of film-makers supporting Pascale Ferran rallied around and arrived in large numbers at the meeting's venue in La Femis, the prestigious Parisian film school. Long queues formed to join the SRF – and therefore vote – as permitted by the statutes. The debate was rowdy, to say the least.

In a nutshell, film producer Emmanuel Finkiel claimed that the labour law would prevent people from creating freely and he won his case because a new board was voted in composed entirely of directors who are against the collective agreement as it stands, including Pascale Ferran, Katell Quillévéré and Sébastien Lifshitz.

The government was to extend the agreement to the entire film industry on 1 July, but aware of the threat to cinematic diversity, has postponed its application until 1 October, allowing time for the reopening of negotiations on fragile films. To get the dialogue going again, the French Society of Cinematographers brought out a special edition of its magazine with the headline "And now what?" in which numerous industry bigwigs have voiced their opinions.

For Agnès Godard, a well-known director of photography who has worked on many of Claire Denis's films, the most important concept is that of working together. "Because that's how a film is made: a large number of people take part in it and commit themselves to it. That's called a team," she said. Clearly the time has come to rebuild bridges in the French film industry.

This article appeared in Guardian Weekly, which incorporates material from Le Monde