Egypt's Supreme Constitutional Court has ruled against parts of an election law approved by the Islamist-led legislature that had lifted a long-standing ban on the use of religious slogans during campaigning.

The court on Saturday said in its decision that not explicitly banning religious slogans in campaigns runs counter to national unity and principles of citizenship. The court says religious slogans may distract voters from focusing on the candidate's platform. The bill will now be sent back for review by the interim parliament.

It similarly ruled against a provision that stipulates media outlets give equal time to candidates, saying this violates freedom of the press.

The court also says the bill breaches the principles of separation of powers because it allows the president to set election dates and change them.