David Gerbi, an exiled Libyan Jew, recently returned to Tripoli from Italy to reopen the city's main synagogue closed by fugitive dictator Moammar Gadhafi's regime 44 years ago.
However on Monday, Gerbi was warned that armed guards were coming from all over Libya and would target him if he did not leave the area.
Gerbi said he was told a mass anti-Jewish demonstration was planned for Friday in the capital's central Martrys' Square, formerly named Green Square under Gadhafi's regime.
He criticized the Libyan authorities for withdrawing their support and said his effort was a test of tolerance in the "new Libya."
"If they want to prove that it's different from Gadhafi. they need to do the opposite," he told reporters after leaving the synagogue.
The head of the National Transitional Council dismissed issue, saying it was too early to worry about rebuilding a synagogue when revolutionary forces were still fighting Gadhafi supporters.
"This matter is premature and we have not decided anything in this regard," Mustafa Abdul-Jalil said.
Gerbi refused to give up, saying he would stay in Libya and press his case with the government.
"I don't want to be a hero, I don't want to play martyr, I just want to be here to support the new Libya and the democracy and to build this," he said.