Manama: Al Wefaq, Bahrain's largest parliamentary bloc, has pulled out of the lower house where it held 18 of the 40 seats.
"Our MPs will not return to the parliament," Abdul Jalil Khalil, the head of the bloc, said at a press conference.
The decision came two days after Al Wefaq froze its participation in the lower chamber over the death of two protesters on Monday and Tuesday.
The society said that its decision to withdraw permanently from the parliament was taken unanimously following the intervention of the security forces on Thursday to force people out of the Pearl Roundabout.
"We will make our strategic options known within days. Seven political societies have agreed on the initial demands and we held an emergency meeting to discuss the latest developments," Abdul Jalil said.
"We stand by the people and uphold their choices. We have to talk about the future of the country because we are at a dangerous crossroads and there is a critical need to find political solutions that will see out of this situation," he said on Thursday evening.
The current lower chamber, voted in last year and which held its first session on December 14, has no significance after the withdrawal of the society that was endorsed by 64 per cent of the voters, Al Wefaq said.
MP Khalil Al Marzooq, the first deputy speaker, called for an end to violence and stressed that Al Wefaq would not reverse its decision to pull out, particularly after the heavy toll of deaths and injuries on Thursday.
"The withdrawal of Al Wefaq means that three parliamentary committees would be stalled and that the parliament cannot continue. This is the least that Al Wefaq can do," he said. Al Wefaq MPs have an outstanding presence in the committees.
However, Al Wefaq did not say whether its members on four of the country's five municipal councils would also pull out.
Al Wefaq boycotted the 2002 parliamentary elections, the first to be held in Bahrain following a three-decade constitutional hiatus and coinciding with a political and constitutional reform programme launched by King Hamad Bin Eisa Al Khalifa.
However, the society in 2006 reversed its decision despite sharp divergences with hardliners who eventually formed a splinter group and made an impressive debut, winning 17 seats and helping an ally secure his constituency.
Last October, the society carried the 18 constituencies where it fielded candidates, all men and a combination of young and old blood.
Khalil Marzooq was elected by his peers on the first session as the first deputy to the Speaker, a position that enabled him to chair sessions in a historic breakthrough for the opposition.
Legal experts will this week wrangle with the issue how Al Wefaq's withdrawal would affect the parliament legally.
According to Fareed Ghazi, a lawyer and a former lawmaker, the parliament's bylaws stipulated individual resignations, but not a mass pullout.
"The parliament can go for a waiting period, giving time to Al Wefaq to reconsider its decision. However, if their absence is prolonged, there might be a need to call in for complementary elections in the constituencies carried by Al Wefaq and which would have no representations," Fareed said.