Opposition says any talks with government must be preceded by "guarantees of seriousness" and include jailed leaders.
Opposition groups in Bahrain have set out principles under which they say they are ready to engage in dialogue with the ruling monarchy to end the political deadlock in the Gulf nation.
The five main opposition associations, led by the Shia al-Wefaq, acknowledged that they had not received any invitation for talks, but said they were preparing in case negotiations were initiated.
“Any offer of dialogue requires consensus on its agenda, means, and duration in order to provide initial guarantee of its seriousness,” the groups said in a statement.
The groups said that the dialogue should include opposition leaders jailed in the wake of a brutal crackdown last year on a pro-democracy uprising.
Jawad Fairouz, a former Wefaq MP, said that while the opposition did not believe talks should go ahead based on any preconditions, they did need to "clarify and find answers to certain issues", including the release of prisoners.
"We insisted that the dialogue include certain principles," said Fairouz. "If we want this dialogue to have a positive reflection on the streets, then the prisoners should be consulted, they should be released. This is not a precondition. But by the end of the dialogue, they must be released."
The statement was released following a meeting of the groups, including the National Democratic Action Association (Waad in Arabic), the Nationalist Democratic Rally Association, Alekha National Society, and National Democratic Assembly.
It also came a day before the release of a report by a commission tasked with gauging progress towards implementing recommendations made last year by the government-sponsored Bahrain Independent Commission of Inquiry (BICI), which documented widespread abuses committed last year during the country's unrest.
Political parties are banned in Bahrain, and licensed associations act as de facto parties.
The five groups said the results of the dialogue should be agreed by the public, and insisted that the outcome should be "revealed to the people so that an agreement can win popular and legal legitimacy."
They reiterated that the dialogue should be based on the offer tabled by Crown Prince Sheikh Salman bin Hamad al-Khalifa days before the crackdown in March last year.
Salman had said he supported vesting the parliament with full powers, and pledged to tackle naturalisation, administrative and financial corruption, and sectarian tensions.
The Shia majority have always complained of using naturalisation to tip the demographic balance in favour of Sunnis loyal to the ruling family.
The opposition also demanded the implementation of the recommendations of the BICI’s probe which accused police of using excessive force against demonstrators and torturing prisoners.
The opposition groups agreed to form a "joint delegation" to any future talks with the government.
Tensions have remained high since the deadly crackdown last year, and protests continue to happen regularly in villages across Bahrain.