Hundreds of people staged a sit-in on Sunday at the Professional Associations Complex to condemn the attack on al-Shbeilat, who formerly served as a parliament member and head of the Jordan Engineering Association.
Al-Shbeilat, who currently heads an organisation for resisting normalisation of ties with Israel, suffered bruises and was hospitalised after he was attacked by five men at a bakery where he was buying bread.
Recounting the assault from a hospital where he said he was undergoing tests and scans, al-Shbeilat told Al Jazeera: "I left my home early morning, and went to the bakery. Apparently, a group of people were following me.
"While I was in the bakery, I felt someone beating me from behind. Some people in the bakery intervened, but the attackers continued beating me and then ran away. Five people got away in a car."
Al-Shbeilat was quoted by local Jordanian newspapers as saying that the attack had come on the heels of a lecture he delivered recently at the Socialist Thought Forum, calling on the government to fight corruption, respect the constitution and to cease all forms of normalisation with Israel.
"I have recently reduced my activities because my colleagues have not taken up the responsibility to talk about what is going on [in the kindgom]," he told Al Jazeera.
"The country is collapsing. There is too much corruption, there is a lot of stealing and looting while the purported opposition is standing silent."
"When I get invited to deliver a lecture - I frequently refuse to do so but they insist - I speak about what I know. This is what is going on.
"Silence of the reform forces over what is going on, is the reason behind this collapse in the country.
"I have repeatedly, during the past years, held the opposition responsible for what is going on. There is no real opposition."