The companies - Foretec, Midi System, SGME and Elektron - currently operate around 90 percent of the 10,000 taps on phone calls and records, text messages and internet activity that take place on an average day.
But their business with the justice ministry is due to end when France launches its National Platform for Judicial Interceptions (PNIJ), which is touted as the biggest electronic surveillance agency in Europe.
They are outraged at what they say was the refusal by the ministry to let them tender to run the new centre, the contract for which was given to the French conglomerate Thales. The centre had been due to go online last year but has been hit by repeated delays.
The four protesting firms have been engaged in a lengthy legal dispute with the ministry to try and get compensation but have had no success.
“We can’t invest any more without being able to know what is going to happen in the future, the banks won’t offer us credit,” said Elektron boss Michel Besnier.
So the firms decided to decline any new wiretaps from midnight on Monday this week.
The move enraged the ministry, which sent out a directive to prosecutors across the country instructing them to fine the firms 750 euros for each wiretap they refuse.
Each company receives around 50 requests a day, so that would add up to a hefty bill if the directive is applied.