Crowds in the Venezuelan capital joined in chants of "We want to vote" yesterday as they faced waits of up to three hours in the heat in one of the tightest elections since President Hugo Chavez stormed to victory in 1998.

Turnout was reported to be high as up to 19 million Venezuelans went to the polls, desperate to take part in the vote that has polarised the nation. Most opinion polls project that the results, which are due to be announced today, could narrowly hand Mr Chavez a fourth presidential term. But this time, the opposition is far more united, and it has fielded Henrique Capriles, a charismatic former regional governor, as its candidate.

Although Venezuelans live with one of the world's highest murder rates, Mr Chavez remains popular, especially among the country's poorest people. When torrential rain and floods ravaged Vargas on the coast of Venezuela, José Luis Aparicio lost everything. "My house was destroyed in the storms," he says of the disaster, which killed around 30,000 people.

But 13 years later, Mr Aparicio is still emphatic about who he thanks for helping him through the aftermath. "Chavez gave me a house. He's given houses to the poor, to retired people, and given us cheap food," he said.

"My friend's daughter had a heart problem, and was going to die," said 57-year-old baker Maria Gomez. "The bill was 400m bolivars. But the government did it for her." Like many "Chavistas", her enthusiasm for Chavez matches the hostility of his opponents. "He's the best President Venezuela has ever had."

But Chavez's opponents, such as 69-year-old Juan Peres, know this has been their best opportunity yet to oust the President. "If this government continues, there is no future for Venezuela," Mr Peres said.

Elsa Chatorro, a 58-year-old housewife, said: "I know how people feel – they want change, liberty, democracy and human rights. I'm scared that the government will not accept it if they lose."

However, Konny Zarrago, a 36-year-old accountant, said such fears are baseless. "There are some prejudices about the government, and the opposition exploits them to create fear," he argued. "They lie."

Election observers from both camps at polling stations in Caracas reported they were happy with the process. However, they shared frustration at delays in voting, caused by problems with fingerprint machines used to identify voters and the prioritising of elderly and disabled voters. Under Venezuelan law, voters could not be turned away, even when polls officially closed last night.

Speaking ahead of the vote, Capriles campaign spokesman Ramon Guillermo Aveledo insisted that the election would be free and fair. "The election process is 100 per cent reliable, we are auditing the process, and will have observers at every polling station," he said.

"Venezuela is not a dictatorship. But that is not because of the decisions of those in power but because of many years of struggle by the Venezuelan people." The claim raised eyebrows among Chavez's advisers, who point to the involvement of senior opposition figures in an unsuccessful US-backed coup in 2002.

Many Capriles supporters have been pragmatic in the face of continued support for Chavez. "I'm not like others voting against Chavez who says everything he does is wrong," said Hugo Urdaneta, a 30-year-old PricewaterhouseCoopers employee. "I just think after 14 years we need a change. If Capriles wins, he needs to keep a lot of Chavez's policies."

The Capriles campaign insists it will preserve popular social policies but pledges to make them more efficient. Rather than calling for the reversal of Chavez's "Bolivarian Revolution", Capriles looks to the more moderate left-wing government in neighbouring Brazil.

Temir Porras, Chavez's Vice-Minister for Europe, acknowledged the opposition had fielded an "intelligent campaign", but argued that it marked an "ideological victory" for the government. "They need to do that to win power. It's impossible to win in Venezuela on a right-wing programme."

If Chavez wins, the opposition will hope for a narrow defeat to lay the foundations for success next time. But given the state of his health – Chavez is recovering from pelvic cancer – and with political divisions as bitter as ever, those hoping this election will bring long-term stability may be disappointed.