Opposition MPs fear that a US-funded education reform package will open the door to American interference in Egyptian schools.
The centrepiece of the package is a $64 million (pound;40.4m) grant from the United States Agency for Development (USAID) which will be used to train Egyptian teachers in the US, improve access to lessons for rural pupils and girls, decentralise services, and promote community involvement.
Members of the Muslim Brothers, Egypt's largest opposition movement, point to a clause in the deal - signed in June - that says those responsible for carrying out the reforms are the ministry of education, US-based charity Care International and "other bodies to be identified later".
The banned but tolerated movement maintains that the Bush administration, claiming that religious teaching encourages terrorism, wants governments to secularise their curricula.
"We are not forcing anything on anyone," said a senior official from USAID, which, despite giving more than $765m to education in Egypt since 1975, keeps a low profile because of widespread anti-American sentiment.
But Mohammad Mursi, head of the Brothers's parliamentary delegation, cited the addition of an "ethics and values" class in schools last year.
"People have been afraid that it might be replacing religion classes," he said, adding that if they tried, "there would be a big revolution against it".
Egypt has begun an aggressive reform campaign, quadrupled spending and built 12,000 schools in the past decade.
But schools are struggling with classes of up to 60 pupils, teacher salaries of just pound;15 a month and a "private lessons" system in which students pay teachers for material that is likely to be in their exams.