Police in Malaysia say anyone attending an opposition rally in Kuala Lumpur on Saturday will be arrested.
The rally for free and fair elections is seen as a test for the government ahead of forthcoming elections.
Police have already arrested more than 200 supporters of the Bersih or "clean" movement that is campaigning for changes to Malaysia's electoral laws.
Bersih is campaigning for an end to gerrymanders that favour the government, a crackdown on fake and bought votes and equal media coverage for the opposition.
The ABC reports intervention by Malaysia's king seemed to have calmed the tension over the protests with the government agreeing to allow a stadium to be used as a venue, but it then reversed that offer declaring the protest illegal.
