Egypt's army-backed government has decided to annul the Muslim Brotherhood's legal registration within days, a newspaper has said.
While short of a formal ban, the move underlines the government's determination to crush deposed president Mohammed Mursi's movement.
The authorities accuse the group that won five successive elections since 2011 of terrorism and inciting violence.
But so far they have failed to snuff out nationwide demonstrations demanding the reinstatement of Mr Mursi, who was ousted by the army on 3 July after mass protests.
The Brotherhood has urged its supporters to fill the streets of Egypt's towns and cities again today, for the third time in eight days, to reject what it calls an army coup against democracy.
Authorities are pursuing the toughest crackdown in decades on the Brotherhood, Egypt's biggest political grouping.
Since July, they have killed more than 900 of Mursi's supporters and arrested most of the movement's leaders, including Mr Mursi, on charges of murder or inciting violence against anti-Brotherhood protesters.
The symbolic move to cancel its legal status applies to the non-governmental organisation registered by the Brotherhood in March as a defence against legal challenges.
The move to dissolve the NGO stems from accusations that the Brotherhood used its headquarters to fire and store weapons and explosives, the privately-owned Al-Shorouk newspaper said, adding that the Brotherhood had failed to respond to the accusations.
The Brotherhood was founded in 1928 and formally dissolved by Egypt's then military rulers in 1954.
It continued to be grudgingly tolerated as a mass movement, however, sending legislators to sit in parliament as independents.
It says it has around a million members.
There has so far been no attempt to ban the Freedom and Justice Party, the political wing that the Brotherhood set up in 2011, after the overthrow of the veteran general-turned-president Hosni Mubarak.