The Venezuelan Government has rejected an opposition call for a vote on a constitutional amendment to allow the term of President Hugo Chavez to be cut short.

The move revives the spectre of prolonged political turbulence in Venezuela, after a 64-day strike had appeared to be faltering.

Long queues are now much rarer than at the height of the strike

Opposition leaders claim they collected four million signatures supporting the initiative, a number double that necessary to call a national referendum.

However, the government said it endorsed another plan - to hold a binding referendum on Mr Chavez's presidency after August.

"We're proposing what we always have: referendum after 19 August as laid down in the constitution," Vice-President Jose Vicente Rangel said.

Carter suggestions

Mr Chavez had previously been reported as saying he would have "no problem" with the referendum.

Both proposals had been put forward by former US President Jimmy Carter as ways out of the crisis.

The first - the constitutional amendment - would have allowed the presidential term to be cut from six years to four years, in this case opening the way for fresh elections early next year.

But the Supreme Court ruled last month that the National Assembly should appoint a new electoral body to verify the opposition petition and, if necessary, set a referendum date.

Chavez: buoyed by 'victory', is in uncompromising mood

Opponents of Mr Chavez branded the ruling politically motivated as it would delay any eventual referendum by months.

They accused the government of hampering negotiations to put an end to the bitter confrontation over Mr Chavez's rule.

"This response takes us further away from the Carter proposal, especially about any electoral date," anti-Chavez union head and opposition negotiator Manuel Cova told the Reuters news agency.

"The government just isn't interested."

Not so generous

Vice-President Rangel also dismissed Mr Carter's call for no reprisals against workers at the state oil company. Output from the world's fifth-largest oil exporter fell from 3.2 million barrels per day to a strike low of just 150,000 barrels.

Mr Chavez has fired more than 5,000 oil company employees. Some had been given their jobs back after being involved in the short-lived coup against Mr Chavez last April.

But correspondents say he looks unlikely to be so generous again.

Reduced oil production remains the most damaging effect of the strike.

Mr Chavez says production is back up to 1.8 million barrels a day, though oil strikers said output still hovers around one million barrels.