Parliament met on Wednesday to debate a law on imposing a state of emergency in Yemen, the scene of deadly protests demanding the end of President Ali Abdullah Saleh's three-decade rule.
The demonstrators, camped at a square near Sanaa University since February 21, urged MPs not to pass the law. "A vote in favour is equivalent to approving the massacre of the innocent," they said in a statement.
The embattled Saleh, who has ruled for more than three decades, announced the state of emergency after 52 demonstrators were gunned down by regime loyalists in Sanaa last Friday.
To take effect the law needs the approval of a majority in the 301-seat parliament, 170 of which are occupied by members of Saleh's General People's Congress although many of them have quit in protest at the government's crackdown on protesters.
On Tuesday, an offer from Saleh to quit by January failed to appease the escalating opposition over the past two months to his 32-year rule.
Saleh, who had previously said he would stay in office until his term runs out in September 2013 but not run again, has offered to quit by January after a parliamentary poll, according to a senior official.
His regime has been hit by a wave of defections in the ranks of the military, among influential tribal chiefs, Muslim clerics and senior diplomats as well as within Saleh's own ruling party.