A meeting between leaders of the seven major political parties is expected to take place later on Tuesday to drum up strategies for fresh protests against King Gyanendra's direct rule over the Himalayan nation.
"We were successful in foiling the king's plans to hold municipal elections earlier this month. Now our focus will be to come up with plans to force the king to give up power he grabbed," said Krishna Sitaula, spokesman of Nepali Congress, the largest party in Nepal.
The king ousted an interim government in February 2005 and formed a new administration under his own chairmanship.
In response, the country's seven major parties formed an alliance aimed at forcing the king to restore democracy.
There have been continued street protests ever since, and the king appealed to the political parties this week for talks. The parties rejected the call.
In the run-up to municipal elections on 8 February the government detained hundreds of dissident politicians and activists in efforts to squash their campaign to disrupt the vote.
The government's efforts largely failed, because the polling drew few candidates and few voters.
The political parties said they would file cases in courts to seek the release of the hundreds of politicians and activists who are still in jail.
King Gyanendra ousted the
government in February 2005
"We are going to file cases at all the courts to seek the freedom for those who are still in jail. We will force the government to release all of political detainees," said Subash Nemwang of the Communist Party of Nepal.
The Supreme Court and lower courts - which have remained largely independent despite the king's firm grip on the government - have been ordering the administration to free dozens of jailed dissidents, saying the government has no reason to hold them.
Despite this trend, the government ordered a one-month extension for the detention of Madhav Kumar Nepal, general-secretary of the Communist Party of Nepal, who was placed under house arrest last month.
The courts have not yet ruled on his detention.
When the king seized power last year, he said it was necessary to quell a festering communist insurgency in the countryside and clean up corruption in the government.
However, fighting between the Maoist insurgents and security forces has since escalated.
The insurgents, inspired by the ideology of Chinese revolutionary, Mao Zedong, want to set up a communist state.
The decade-old insurgency has claimed more than 13,000 lives.