The first police protest in France in three decades comes after an officer was seriously injured last week in a shootout with a criminal who committed a robbery after going on the run during a leave of absence from prison.
The shooting infuriated a force already stretched to breaking point as they remain on high alert for terrorist attacks while having to deal with everyday crimes.
"The police, heroes in January, have been forgotten," said Jean-Claude Delage of the police union Alliance.
Three police officers were shot dead when Islamist gunmen carried out a string of attacks in Paris in January that left 17 dead, including much of the editorial team of the satirical magazine Charlie Hebdo.
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The deaths of their colleagues and the dramatic hunt and shooting dead of the three jihadists led to an outpouring of support for the police, who were greeted with spontaneous applause and shouts of "thank you" at a mass rally after the three-day killing spree.
For Patrice Ribeiro of Synergie, the second biggest police union, the problem is "despondency, a loss of the meaning of their job."
All the unions complain about an "explosion of violence", a "lack of resources", "unclear missions" and a "lack of solutions from the criminal justice system".
The police officers will protest outside the offices of Justice Minister Christiane Taubira in the Place Vendome square in Paris, reviving an old enmity between the police service and justice ministry in France.
The last police protest took place in 1983 when some 1,500 officers took to the streets to criticise government policy under president Francois Mitterrand after two policemen were killed by an extreme-left grouping.
President Francois Hollande said today he would meet with police unions next week, according to government spokesman Stephane Le Foll.