In an unprecedented show of defiance, protesters including many elderly people and housewives paralysed the Armenian capital, with nearly all streets closed to traffic and numerous stores shut.
Officials said that suburban train services were disrupted and the road linking Yerevan with its airport was blocked.
Crowds of protesters across the city of one million people waved national flags, blew vuvuzelas and shouted “Free, independent Armenia!”.
Leading supporters on a march through the city, Mr Pashinyan pledged to ramp up pressure on the authorities.
“Various scenarios are under discussion, under each scenario the people will win,” said Mr Pashinyan, who was wearing his trademark khaki-coloured T-shirt and a baseball cap.
The underground system and railways have been paralysed and a number of universities and schools have joined the protest movement, he added.
In parliament, lawmakers could not convene for a session due to the absence of a quorum, with the opposition Prosperous Armenia party declaring a boycott.
“There is an emergency situation in the country. Our faction declares a political boycott,” said Prosperous Armenia lawmaker Vahe Enfiajyan.
Under Armenian law parliament should again gather in a week to try and elect a prime minister. If it fails, the legislature will be dissolved and early elections called.
In the second city of Gyumri – which hosts a Russian military base – and the smaller town of Maralik demonstrators occupied the mayor’s office and demanded local authorities join the protest movement.
Mr Pashinyan urged Armenians to launch a general strike after the ruling Republican Party on Tuesday blocked his bid for prime minister following two weeks of anti-government protests that ousted veteran leader Serzh Sarkisian.
Protesters said they would stay on the streets for as long as it takes to oust the ruling elites from power and get Mr Pashinyan elected premier.
“The people will not give up, protests will not subside,” Sergey Konsulyan, a 45-year-old businessman.