The coalition, led by Mohamed ElBaradei until his appointment as Vice-President in the new Government, complained of a lack of consultation before the charter was adopted.
"We call for it to be amended and will propose our own amendments to the President," the group added
The appointment of economist Hazem el-Beblawi as Prime Minister, along with the setting of the accelerated timetable, underlined the army's determination to push ahead in the face of Islamist opposition and outrage over the killing of more than 50 Morsi supporters.
Saudi Arabia and the United Arab Emirates provided a welcome boost for the new leadership. The two countries, both opponents of Morsi's Brotherhood, celebrated his ouster by showering the cash-strapped Egyptian Government with promises of billions in grants, loans and badly needed gas and oil.
In doing so, they are effectively stepping in for Morsi's Gulf patron, Qatar, a close ally of the Brotherhood that gave his Government billions in aid. During Morsi's year in office, he and his officials toured multiple countries seeking cash to prop up rapidly draining foreign currency reserves and plug mounting deficits, at times getting the cold shoulder.
The developments underlined the pressures on the new leaders, even with the country still in turmoil after what Morsi's supporters have called a coup against democracy.
The military faces calls, from the US and Western allies in particular, to show that civilians are in charge and Egypt is on track to a democratically based leadership.
The new Government will soon face demands to tackle economic woes that mounted under Morsi, including fuel shortages, electricity cuts and inflation.