Bolivia's interim President Jeanine Anez sought on Monday to reshuffle her government after coming under fire over her decision to stand in the May 3 presidential elections.

The right-wing president demanded on Sunday that all 20 of her ministers resign, in what Bolivia’s media said was an attempt to present a united front in the run-up to the polls.

“The vast majority have submitted their resignations” by midday on Monday, the minister with responsibility for presidential affairs, Yerko Nunez, told a news conference in La Paz.

The new cabinet is expected to be named on Tuesday, Nunez said, adding that “some ministers will be confirmed and others not”, without giving details.

Anez issued her resignation demand on Sunday, hours after communications minister Roxana Lizarraga quit in protest at her decision to stand as a candidate in the May 3 election.

Media reports in La Paz said Anez wanted to shed ministers loyal to Luis Fernando Camacho, a powerful regional politician who was instrumental in the protests that led to ex-president Evo Morales’s resignation on November 10.

Camacho – initially a supporter of Anez’s government – later joined her critics and is himself a candidate for the presidency.

At least three members of Anez’s cabinet are seen as strong “Camachistas” – among them Defence Minister Luis Fernando Lopez.

Meanwhile, Luis Arce, the candidate for Morales’s Movement for Socialism party, said he would return to Bolivia Tuesday from exile in Mexico to begin campaigning.

“Tomorrow I’m going to be in Bolivia,” Arce told a news conference during a stopover in the Argentine capital Buenos Aires, where Morales – who appeared alongside him – is based.

Arce, a 56-year-old former economy minister, wasted no time in joining the growing criticism of the authoritarian Anez.

“The fact that the de facto president is running raises huge questions about the transparency of the electoral process,” Arce told reporters.

Anez assumed the presidency on November 12, two days after Morales resigned following three weeks of sometimes violent protests against his controversial re-election in a poll the Organization of American States said was rigged.

Lizarraga on Sunday was the first member of the government to openly criticise Anez since the little-known former senator assumed the presidency on November 12.

She slammed the right-wing leader for having “lost sight of her objectives”.

Lizarraga said Anez had “started to fall into the same evils” as the party of her predecessor Evo Morales.

“This is not the path the citizenry has signalled to us,” said Lizarraga.

Arce was given asylum in Mexico like Morales, though Morales gave up his Mexico City refuge in December to base his political operation in Argentina.

Former presidents Carlos Mesa and Jorge Quiroga have also joined the presidential race along Camacho.

The Movement for Socialism has been leading in the polls, with 26 per cent of voter preferences compared to just 12 per cent for Anez, who is running fourth.

“In all the polls we are first,” Morales tweeted in reaction. “We are ready to beat the coup and regain the homeland.”