Hundreds of anti-war campaigners descended on UAV Engines in Shenstone on July 6 despite the company securing an injunction banning them from demonstrating within 250 metres of the site, which makes drone parts.
Staffordshire Police arrested 19 people on the day in heated scenes which saw a wall of officers physically push back the lobbyists along Lynn Lane towards the railway station.
But this week, the part of the order imposing the exclusion zone was overturned in the High Court and campaigners have now called for the cases against those who were detained to be dropped.
A further hearing will take place in September concerning the rest of the injunction which includes restrictions around interfering with employees going to and from the factory as well as trespassing on company property.
Ryvka Barnard of War on Want, one of more than 25 campaign groups that took part in the protest, said: "We are calling for any charges against the 19 people arrested to be dropped the real criminals here are the companies making and selling deadly weapons.
"We reiterate our demand for an immediate two-way arms embargo on Israel. This injunction is anti-democratic and criminalises legitimate protest.
"Fortunately, the court has realised its error with regard to the forbidden area and will hopefully now lift this draconian injunction entirely.
"We will continue to assert our right to protest at factories producing weapons used in human rights abuses and war crimes."
Chris Cole, from Drone Campaign Network, added: "We're very pleased that the High Court has decided that the injunction sought by UAV Engines went too far and curtailed the right of legitimate and peaceful protest outside its premises.
"Arms companies like UAV Engines must accept that many people have serious and legitimate objection to their activities."
The 19 people arrested remain on bail until July 31 and Staffordshire Police could not say how the latest development would affect the cases.
Elbit Systems, the parent company of UAV Engines, have not addressed allegations they have supplied drone parts to Israel which are suspected to have been used in military assaults on the Gaza strip last summer killing more 2,200 Palestinians.
The company again declined to comment in relation to the latest court ruling.