The General People's Congress warned in a statement that any sanctions would only exacerbate the crisis in Yemen, where Saleh is seen as the prime backer of Shiite rebels who have overrun the capital and other areas since September.
The UN Security Council was poised to endorse a US-drafted proposal to slap a visa ban and assets freeze on Saleh and two of his allies, Shiite Huthi rebel commanders Abd al-Khaliq al-Huthi and Abdullah Yahya al-Hakim, diplomats in New York said on Tuesday.
"Any sanction would have dangerous consequences that would threaten not only the security of Yemen, but also that of its neighbours," the GPC warned.
The party said its supporters and allies would "confront any sanctions with all peaceful means". It called for protests across the country on Friday to reject "all of forms of intervention".
Saleh was Yemen's first president after unification in 1990 before being forced to step down in February 2012 under a regional peace plan.
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But he is seen as the prime backer of the rebel Huthi movement that seized the capital in September and has since spread its control into central and west Yemen, in defiance of a UN peace plan.
Abd al-Khaliq al-Huthi is the younger brother of chief rebel leader Abdulmalik al-Huthi and was among commanders who oversaw the storming of Sanaa.
Hakim is Abdulmalik al-Huthi's military second-in-command.
A Security Council committee met on Tuesday to discuss the proposed sanctions and the talks were "constructive", a diplomat said.
The 15 members of the council now have until Friday evening to raise objections before the proposal returns to the sanctions committee for action.
The top UN body in August called on the Huthi rebels to end their armed uprising against President Abdrabuh Mansur Hadi and warned of sanctions against those who threaten the stability of Yemen.