Venezuelan public sector workers who signed a petition backing a referendum to recall President Nicolas Maduro could face dismissal, a spokesman of the governing Socialist Party said.
The spokesman said President Maduro had ordered that any manager in five key ministries who signed the petition should be sacked.
The petition is the first step towards a referendum which could see Mr Maduro ousted.
Mr Maduro has been in power since 2013.
48-hour deadline
He is a supporter of the “Bolivarian Revolution”, the socialist movement his predecessor in office, Hugo Chavez, founded.
Government critics argue that their socialist policies have driven Venezuela into a severe economic crisis.
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They have called for a recall referendum to be held this year to remove Mr Maduro from the presidency and trigger fresh elections.
They handed in a petition to that effect in May signed by almost two million people, many more than the 1% of registered voters they needed.
Flowchart of next stages of the Venezuelan recall referendum
On Monday, Socialist Party (PSUV) spokesman Jorge Rodriguez said that those in senior public positions who had signed the petition would have to leave their posts.
“Today, by order of the [governing Socialist] party president Nicolas Maduro, five ministries … cannot have people that are against the Revolution and the president in management positions”.
He said that President Maduro had given the ministries of food, basic industries and finance among others a deadline of 48 hours to dismiss those in senior positions who had signed the petition.
Race against time
The announcement follows reports by pressure groups and opposition parties that public sector workers who had signed the petition were pressured and sometimes sacked.
A supporter of the Venezuelan opposition holds a banner reading Image copyrightEPA
Image caption
Opposition politicians have urged their supporters to take to the streets on 1 September to demand a recall referendum
Opposition politicians behind the drive for a recall referendum say the government is doing everything in its power to try to derail, or at least delay, the referendum.
The electoral authorities have told the opposition that they can only start collecting signatures in late October for the second petition needed to trigger a referendum.
Timing is key as the date when the referendum is held will determine what happens next.
If a referendum should go against the president before 10 January, new elections will be held, which the opposition hopes to win.
But if it is held after that date and Mr Maduro is recalled, his loyal vice-president will serve out the end of his term until 2019.
The opposition has called on its supporters to join a protest march on 1 September to demand that the electoral authorities allow the referendum to go ahead before the 10 January, which marks the day when Mr Maduro will have served four years in office.