Egyptian human rights groups condemned Wednesday an impending trial of 43 democracy activists as politically motivated, accusing the authorities of intentionally misleading the public to retain power.
In December, prosecutors and special forces raided 17 nongovernmental organisations' offices and confiscated their equipment.
Last month, they announced that dozens of Egyptians, Americans and activists of other nationalities had been referred to a criminal court.
That has deepened a rift between Egypt and its traditional US ally, with American lawmakers warning the crackdown could jeopardise more than $1 billion in annual US aid to Egypt.
And that drew a veiled warning Wednesday from the Islamist party that dominates Egypt's parliament that the future of its peace treaty with Israel could be in jeopardy if Washington cuts off that aid.
The 29 rights groups, including the Egyptian Initiative for Personal Rights, the Egyptian Organisation for Human Rights and the Cairo Institute for Human Rights Studies, condemned the trial as "politically motivated."
They accused the authorities of conducting a smear campaign against rights advocates.
"Even before the trial has begun, the ministry of justice, other government parties and the two investigating judges have been conducting a one-sided trial in the media for the past five months, making vague accusations," they said.
The groups accuse authorities of shackling the independence of the judiciary and of handpicking the two investigating judges, Sameh Abu Zeid and Ashraf Ashmawi.
"The investigations are taking place in a government office (the justice ministry), and the two investigating judges were handpicked."
The groups said the two judges had worked long stints as heads of the High State Security Prosecution, which "is complicit in covering up the torture of defendants by the (now-dissolved) State Security Investigations in political cases and functioned as a tool of the (Hosni) Mubarak regime."
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The probe was done with "the goal of smearing civil society, especially human rights organisations, and painting them as collaborators with foreign agendas and conspirators against the country's stability," they wrote.
"This is a flagrant violation of the law and investigation rules."
The rights groups said the investigation and trials aim to suggest the existence of a "wide-ranging conspiracy targeting the stability and unity of the country and to paint international civil society groups as a danger to state security."
"The orchestration of fictitious battles with other states to distract attention from the catastrophic failure of the political administration and from the daily massacre of Egyptians without accountability ... cannot in any way be a national objective," they said.
"Rather it serves the interest of a small faction that seeks to seize power and wealth without accountability and oversight."
Authorities in Egypt accuse the groups of undermining the military-run government during a fragile transition following last year's ouster of longtime ruler Hosni Mubarak.
An Egyptian minister seen as the driving force behind the trials had told investigators that Washington funded their groups to create a state of prolonged chaos in Egypt.
"The United States and Israel could not create a state of chaos and work to maintain it in Egypt directly, so they used direct funding to organisations, especially American, as a means of implementing these goals," said Fayza Abul Naga, one of the few remaining ministers from the Mubarak era.
Meanwhile, the head of the Muslim Brotherhood's Freedom and Justice Party, Mohammed Morsi, warned that the peace treaty with Israel could come under review if US aid were cut off.
"American aid is a part of the Camp David accord between Egypt and Israel ... There is no place for discussing the aid outside the framework of that accord," Morsi said in a statement.
"The American administration's raising the threat of stopping the aid is inappropriate; otherwise the accord will be re-examined and it could stumble."