"It is time for the Egyptian government to know it is the people's right to know and participate," the groups said.
They said it is people's right to know how much is being spent to bolster the security forces, for example, and the specifics of what is being spent on education and healthcare.
Opposition activist Ali Soliman, a member of one of the opposition groups involved in the lawsuit, said he does not trust the Shura Council to actively debate the budget since it is packed with Brotherhood lawmakers and allies of the president.
"It's as if the Muslim Brotherhood is presenting the budget to themselves," he told The Associated Press.
Some of the groups also are questioning the legality of the Shura Council to act as a legislature. The country's high court is set to rule on its constitutionality next month. The body was elected under the same laws that led to the dissolution of the law-making lower house of parliament last year.
"Any talk that questions the legitimacy of this body is rejected," Brotherhood Shura Council member Mohammed Abdel-Maguid said. "People went out and voted in free elections and elected us."
Abdel-Maguid also is head of the body's economic committee. He told the AP that lawmakers will make a website for citizens to submit suggestions about the budget, which he said they intend to make public. He did not give a timeframe.
He said that almost a quarter of the government's spending in the coming fiscal year will be on subsidies. Typically, Egypt has spent around a third of its national budget on subsidies.
Egypt's largest investment bank, EFG-Hermes, said in a report released this week that the draft budget shows an "unrealistic timeline for reforms" and said that the draft budget was "overly optimistic."
According to the report, the proposed budget projects tax revenues to increase by some $13 billion. A significant portion of expenditures will be spent on wages, which are expected to be $4 billion more than the current year's budget.