Nour Party member and candidate in the current parliamentary elections, Emad El-Mahdy, was stabbed in front of his campaign headquarters in Egypt's Sharqiya governorate, the candidate's Facebook page said.
The attacker fled immediately after stabbing the candidate.
El-Mahdy was immediately transported to the nearest hospital in Zagazig city, north east of Cairo.
This incident marks the third time that a Nour Party candidate has been attacked during the current parliamentary elections.
On 27 October, Mahmoud Abdel-Hamid, who is running for an individual seat in Gharbiya governorate, was forced out of his car and assaulted by two men.
Abdel-Hamid was taken to Kafr El-Sheikh hospital suffering from severe head injuries, internal bleeding and a concussion.
Another Nour Party candidate, Mostafa Abdel-Rahman, was shot dead on 24 October while leaving his house in Al-Arish in North Sinai.
Nour is the only Islamist party that is participating in the ongoing parliamentary elections in Egypt. They are also the only Islamist party that supported the ouster of Muslim Brotherhood president Mohamed Morsi in July 2013.
The long-delayed parliamentary elections began in October, with voters in 14 of 27 governorates heading to the polls.
Voters in the remaining 13 governorates, including Gharbiya, North Sinai, and Cairo, will go to the polls on 22-23 November.