The Muslim Brotherhood and other Islamist groups issued a statement Thursday night saying that the venue for a planned million-man protest on Saturday had been moved from Cairo's Tahrir Square to outside Cairo University.

Dubbed the protest to "support legitimacy and Islamic law," the rally is meant to support President Mohamed Morsi and his recent constitutional declaration, which has further polarised Egypt's political scene since being announced one week ago.

Despite the decision to change the protest venue, Islamist groups sterss that they have "every right to hold million-man rallies in Tahrir Square if necessary."

The groups said the move was taken "to protect Egypt's national interests against division and conflict."

A number of political parties and movements had condemned the original decision to hold the protest in Tahrir while a rival sit-in by anti-Morsi groups was still present in the flashpoint square.

According to a statement issued by groups opposed to Morsi and his decree, the president and the Brotherhood from which he hails "have disregarded the simplest rules of political responsibility by calling for the president's supporters and members of his group to protest at Tahrir Square on Saturday."

The statement by Islamist groups, meanwhile, asserts that Islamist forces have the ability to rally millions of supporters to Tahrir Square, stressing that the square belongs to all Egyptians. "It's wrong for any political, partisan or revolutionary faction to bar others from protesting in the square," the statement reads.

In addition to the Muslim Brotherhood, the statement was signed by the Salafist Nour Party, the Jamaa Islamiya and its Building and Development Party, the Salafist Asala Party, and others.

On Tuesday, the Brotherhood cancelled a planned mass rally at Cairo University in support of the president's constitutional declaration. The same day saw massive protests in Tahrir against the president's controversial move.

According to a leading Brotherhood figure, Tuesday's pro-Morsi protests were postponed in order to "avoid any bloodshed and out of concern for the nation's security."