Egyptians should be aware of the possible consequences if planned 30 June anti-government demonstrations turn violent, Mohamed El-Beltagi, leading member of the Muslim Brotherhood's Freedom and Justice Party, said on Thursday.
"The spilling of blood can turn political divisions into an unstoppable sectarian battle," he warned via Facebook.
Egypt is expected to witness nationwide protests against President Mohamed Morsi on 30 June, which will mark the end of the first year of his presidential term.
"The real revolution will end [if sectarian war erupts], relieving the former regime of the consequences of the revolution...it will be the death knell of the revolution, and the triumph of the counter-revolution," he added.
If the 30 June rallies turn violent, El-Beltagy asserted, this would only serve the former regime by pitting Egypt's various post-revolution forces against one another.
He also stressed the importance of reaching consensus, and called on all parties to avoid violence.
Earlier on Saturday, former opposition MP Mustafa El-Naggar also warned that anticipated violence on 30 June could mark the beginning of a "full-scale civil war" in Egypt.
He called on Islamist parties and groups not to stage counter-protests against anti-Morsi demonstrators.
The 'Rebel' campaign, a signature drive that aims to gather 15 million signatures in support of a "withdrawal of confidence" from President Mohamed Morsi, has called for mass protests outside the presidential palace on 30 June.
Turnout for the planned protests is expected to be high, with many opposition political forces and former regime loyalists expressing their readiness to participate.
Figures from the Muslim Brotherhood, the group from which Morsi hails, along with other Islamist forces, have recently announced plans to hold their own counter-rallies on the same day in support of the president.