The Salafist Nour Party's representative on the constitution panel has laid out his conditions for accepting changes to the status of Sharia law in the amended charter.
Salah Abdel-Maaboud told the privately-owned Al-Hayat channel on Tuesday that his party would agree to the removal of Article 219 if the word 'principles' is removed from Article Two.
Article Two currently says Islam is the state religion, Arabic is its official language and the principles of Islamic Sharia law form the main source of legislation.
If 'principles' is removed it would allow for the stricter application of Sharia law.
He said his party would take a firm stance if its suggestions are ignored and denied rumours he would not resign from the panel over the issue.
Article 219 defines Sharia broadly and serves as an explanatory article to interpret Article Two.
It says: "The principles of Islamic Sharia include its commonly accepted interpretations, its fundamental and jurisprudential rules and its widely considered sources, as stated by the schools of Sunna and Gamaa."
Critics have described the article as discriminatory against non-Sunni religious minorities.
Nour had been against removing the article because it would undermine "Egypt's Islamic identity."
Egypt's 2012 constitution was temporarily suspended when Islamist president Mohamed Morsi was ousted on 3 July.
A 50-member committee is currently amending the constitution as part of a transitional roadmap.
The amended charter will be presented to interim President Adly Mansour in early December for approval and will then be subject to a national referendum.