Police will only protect state institutions, not the Muslim Brotherhood headquarters, during opposition protests on 30 June, Interior Minister Mohamed Ibrahim said on Tuesday.
The presidential guard is the only force responsible for protecting the presidential palace, Ibrahim added, but police will offer support if requested.
The palace has witnessed a number of clashes between supporters and opponents of President Mohamed Morsi. The worst outbreak of violence, on 5 December 2012, killed at least 10 and injured more than 600.
Police will not guard the Muslim Brotherhood HQ, which also witnessed protests and violence the past few months, or those of other political parties, Ibrahim stated.
The Rebel (tamarod) campaign has accused the interior ministry of failing to protect its headquarters in downtown Cairo which was torched on Friday.
Minister Ibrahim said police would not stop protests on 30 June, but was silent on whether they would protect opposition 'Rebel' supporters from pro-Morsi groups who have decided to stage counter rallies.
Assem Abdel-Maged, a leading member of Egypt's ultra-conservative Al-Jamaa Al-Islamiya movement, had earlier said that "there is no limit to what might be done to protect the legitimacy [of the president] and the state."
The Rebel campaign, a signature drive launched in May with the intention of "withdrawing confidence" from Morsi by collecting 15 million citizens' endorsements, has called for mass protests on 30 June to demand Morsi's ouster.
Late in May, the campaign announced collecting seven million endorsements.
Citing Egypt's increasingly dire economic situation, the Rebel campaign has called for nationwide protests to coincide with the end of Morsi's first year as president on 30 June.
Morsi, who hails from the Muslim Brotherhood, was elected last year in Egypt's first post-Mubarak presidential elections.