Chile’s stock market dived after voters backed hard-left, radical and independent candidates to write the country’s new constitution, in a poll that largely shunned traditional parties of the left and right.

Investors were particularly alarmed by the poor performance of President Sebastián Piñera’s ruling centre-right coalition, Chile Vamos. It won only 37 of the 155 seats in the constitutional assembly, far short of the one-third required to block major changes.

Chile suffered weeks of sometimes violent social protests in 2019, which were calmed by a decision in a referendum to draw up a new constitution to address longstanding grievances over inequality and inadequate pensions and public services.

However, the results of the weekend constituent assembly election defied forecasts of a moderate body. The traditional centre-left managed only 25 seats, official results showed, meaning that the left and right blocs, which have dominated Chilean politics since the Pinochet dictatorship ended in 1990, managed only 62 seats between them, just over a third of the assembly.

Instead, the results suggested that two radical blocs — one hard left including the communists, and the other of independent leftists — appeared to have secured between them 52 seats in the new chamber, allowing them to block any changes they dislike. Another 30 seats went to indigenous representatives and regionalist groupings.

Interpretation of the results was made harder by the plethora of independents elected, many of them little-known.

Gabriel Boric, of the far-left Broad Front, predicted that the election would mean major changes in Chile, the world’s largest copper producer. “We are looking for a new treaty for our indigenous populations, to recover our natural resources, build a state that guarantees universal social rights,” he said, according to Reuters. “We’re going to start from scratch and build a new Chile”.

Piñera, meanwhile, said that “citizens have sent a loud, clear message to traditional political forces”.

Turnout in the complex election, which also included gubernatorial, mayoral and municipal polls that were postponed because of the pandemic, was just 43 per cent for the members of the constitutional assembly, compared with 51 per cent who voted in the referendum last year, four-fifths of whom opted for a new charter*.

“People with vague convictions didn’t go to the polls, while people with intense convictions did go,” said Andrés Velasco, a former Chilean finance minister who is dean of public policy at the London School of Economics.

Chile has not been spared the coronavirus second wave that has hit Latin America despite it having the highest vaccination rates in the region. Confirmed infections reached their highest-ever level last month, although numbers have since declined.

The country has in recent decades become one of Latin America’s wealthiest nations, but remains an unequal society. The 2019 protests were triggered by a fare rise on the Santiago metro but quickly snowballed into weeks of riots which presented a major challenge to Piñera’s government.

Piñera, a billionaire former businessman, has repeatedly been accused of being out of touch, and the government has suffered repeated defeats in Congress, notably over pensions reform. Chile will elect a new president in November.

*This story has been amended to clarify the number of assembly members who voted for a new charter in the referendum.