“By bringing out new plans all the time, the government could completely worry people and even lead them to panic buy,” Dietmar Bartsch, co-leader of Die Linke (The Left Party) told the Rheinische Post on Monday.
The government shouldn't be adding to the sense of fear on a daily basis, Bartsch added.
Bartsch was responding to Interior Ministry plans published in the Frankfurter Allgemeine Zeitung (FAZ) on Sunday, advising people to stockpile food for ten days and water for five days - an estimated two litres per person per day.
The plan, which makes civilian backing of troops a priority while boosting the resilience of buildings and increasing capacity in the healthcare system, is due to be adopted by the government on Wednesday.
The proposal is Germany's first civil defence strategy since the end of the Cold War.
So far during August, Interior Minister Thomas de Maiziere has made two much-debated announcements on proposals believed to have been developed in response to three bloody attacks in Bavaria in July, two of which had Islamist links, and the third of which, a gun spree in Munich, involved the deaths of ten people.
The teenager responsible for the Munich gun spree is not believed to have had any political motivation for his actions.
In the first raft of proposals, de Maiziere threatened to strip citizenship from jihadi fighters who have dual citizenship, as well as completely doing away with dual nationality.
Last week he also came out in favour of a partial ban on the burqa in public spaces, saying that showing one's face “belongs to our culture.”