CAIRO — New cracks emerged in the government of Egyptian President Mohammed Morsi on Sunday over his decree claiming power beyond the review of any court in the country, which has been met with loud protests.

While Morsi defended his decree and insisted that it was temporary, his justice minister, Ahmed Mekki, began arguing publicly for a retreat that might defuse an escalating battle between Egypt’s new Islamist leaders and the institutions of its old secular authoritarian government.