Gatignon told France 24 that Sevran, once an industrial hub, is "in an extremely difficult situation."
"We've been fighting for years but crisis has made things worse, so I decided to take extreme measures," he said of his hunger strike while camped outside the National Assembly in Paris.
Sevran has been blighted by unemployment and poverty since the 1980s and '90s when companies such as Kodak closed operations there, France 24 said.
Gatignon has asked the government for $6.4 million in subsidies for Sevran and additional grants for other impoverished urban areas in the country.
"In very concrete terms, if we don't get the money, we will not be able to ask for a loan," Gatignon said. "Work on construction sites would have to stop, which would leave people unemployed."
Sevran residents and politicians such as French Interior Minister Manuel Valls have thrown their support behind Gatignon's efforts.
Francois Lamy, junior minister for French towns and cities, announced Sunday that Sevron would receive $5.9 million for urban renewal that had previously been held up.
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