Venezuela's opposition groups are calling for vigilance as voting closes

Voting is closing in Venezuela's presidential election, with Nicolás Maduro of the ruling PSUV party seeking a third term in office.

Polling stations were supposed to close at 18:00 local time (22:00 GMT), but should remain open if people are still standing in line to vote.

Mr Maduro's main challenger is Edmundo González, a former ambassador backed by a coalition of opposition parties.

The opposition called on supporters to remain vigilant at their polling stations to ensure the counting process in the “crucial hours” after the close, amid widespread fears that the PSUV will try to steal the vote.

Opinion polls have suggested Mr González has a large lead over the incumbent, but with Mr Maduro's 2018 election widely dismissed as neither free nor fair, there are concerns that the outcome of the election could be swayed, if not by Mr Maduro. Maduro's way.

The opponents of the president have overcome many obstacles in the run-up to the election, not to mention the fact that their chosen one, María Corina Machado, was barred from contesting the election.

Mrs. Machado, who is at the forefront of the opposition's campaign, reminded the voters that the legal counting process should have been visible to the public.

He called on “all Venezuelans to stay at their polling stations… stay tuned”.

The PSUV has ruled Venezuela for the past 25 years – first under the late Hugo Chávez, then under his hand-picked successor, Mr Maduro.

Under his leadership, the PSUV gained control not only of the executive and legislative bodies, but also of most of the judiciary.

Since assuming the presidency in 2013, Mr Maduro has overseen an economic collapse, with GDP falling by 70% and more than 7.7 million people fleeing the country in search of a better life.

If he wins, Mr González said he will do “everything he can” to bring back those who left.

But Mr Maduro has said he intends to win the election “by hook or by crook” and has warned of a “bloodbath” if he loses.

The National Electoral Council (CNE) – the body that organizes the elections and announces the official result – is full of people loyal to the government.

Its president, Elvis Amoroso, is a close friend of Mr Maduro.

Venezuela has the world's largest oil economy, but its oil output has plummeted under President Maduro – the result of a combination of lack of investment, mismanagement and oil sanctions.

The lifting of oil sanctions – imposed by the US to put pressure on Mr Maduro following the 2018 presidential election – could have an impact on global oil prices.

Voting in Venezuela is done electronically. Voters press a button assigned to their preferred candidate on a voting machine.

The electronic results are sent to the CNE headquarters, but the voting machine also prints a paper receipt which is then placed in the ballot box.

According to the law, the parties are allowed to send witnesses to the counting of these paper receipts carried out at each polling station.

It will be these statistics that the opposition parties will monitor to see if they are consistent with the results announced by the CNE.