Egyptian protesters return to Tahrir square. Reuters

Tens of thousands of Egyptians have returned to Tahrir Square to protest against the military junta, in one of the biggest protests seen in the country since the toppling of Hosni Mubarak.

Although there have been scattered demonstrations against the ruling generals in recent months, Friday's rally was the largest and most explicit display of public opposition to the Supreme Council of the Armed Forces (Scaf) since it took power in February this year.

Reprising many of the slogans that dominated the anti-Mubarak uprising, protesters chanted: "The people want the downfall of the field marshal [referring to the Scaf head, Mohamed Hussein Tantawi]" and "We're not leaving, he is leaving."

The protest brought together Egyptians from across the political spectrum, 10 days before nationwide parliamentary elections get under way. Some liberal parties decided to boycott the rally and criticised the prevalence of the Muslim Brotherhood and Salafi groups in the square.

Both Islamists and secular forces have been alarmed at recent efforts by the Scaf to impose a set of "supra-constitutional principles" on the process of writing a new constitution next year, a move critics say will entrench military control over civilian politics.

Ramy el-Swissy, of the pro-revolutionary April 6th movement, which participated in the rally, said: "The whole of Egyptian society is represented here [with] one demand: for the army to go back to its barracks and return our nation to civilian rule. People who think Egyptians are tired of protesting need only look around them to see the reality. We have to come and speak here today because those in power no longer speak for us."

Osama Farag, a Cairo-based engineer, said the upcoming vote would be meaningless if it was not accompanied by a transfer of power away from the armed forces.

"Ten months on [from the original anti-Mubarak rallies in Tahrir] I didn't expect to be here again, but the military has broken its promises," Farag said. "At present the new parliament looks set to be comic or tragic … there is a continuous harassment of the Egyptian people by the military government and it has to stop."

Similar demonstrations were held in the port city of Alexandria as well as other towns in the Nile delta and upper Egypt.