With the elections scheduled to begin in April, the Islamists who dominated the 2011-12 parliamentary and presidential votes appear more vulnerable than at any time since the ouster of President Hosni Mubarak two years ago. President Mohamed Morsi, of the Muslim Brotherhood’s political arm, is presiding over a period of political polarization, street violence, economic hardship and the first steps of cutting public subsidies. Among the pockets of vocal discontent are the cities along the Suez Canal, which are revolting against his government and apparently eager to vote for almost any viable alternative.

Nonetheless, the boycott by the coalition, known as the National Salvation Front, underscores the depth of its animosity toward the governing Islamists. And it reveals the opposition’s continuing distrust of Egypt’s nascent political process…

In addition to the immediate replacement of the cabinet with a unity government, the front has demanded the removal of the prosecutor general appointed by Mr. Morsi, the spokesman said. He said it also continued to demand “the formation of a committee to redraft the Constitution,” which voters approved in a referendum in December. The coalition opposed the Constitution at the time.