Argentina's two presidential candidates on Sunday claimed the other was lying and running from his record during a debate filled with barbs that were clearly aimed at appealing to undecided voters a week before an historic runoff election.

Ruling party candidate Daniel Scioli, the chosen successor of outgoing President Cristina Fernandez, said the economic ideas of opposition candidate Mauricio Macri "were a danger for society" and would "bring Argentina to its knees."

Scioli, the governor of the vast Buenos Aires province, argued that a devaluation of the Argentine peso was inevitable under Macri, as were cuts to popular social welfare programs for the poor and subsidies for everything from gas bills to bus fares.

"Who is going to pay for the huge devaluation?" said Scioli.

Macri, the mayor of Buenos Aires who has run on free-market ideas, countered that the biggest problem facing the country was a government that "never stopped lying to people."

Macri said that lowering poverty rates by revitalizing sagging sectors of the economy, such as the national railroad system, would be a central focus on his administration.

"I don't think people are afraid" of changes, said Macri, speaking Scioli. "I think you all are the ones who are afraid because you have abused power."

The election comes at a time when Latin America's third largest economy is stagnated. Many Argentines are frustrated by inflation near 30 percent, restrictions on buying U.S. dollars and few job opportunities.

At the same time, Argentines have nightmarish memories of the country's 2001-2002 financial crisis, when Argentina defaulted on $100 billion in debt and millions were plunged into poverty. That recent history makes any discussion of economic changes particularly sensitive.

In last month's presidential election, Scioli got 37 percent of the vote compared to 34 percent for Macri. The tight finished means a runoff on Nov. 22.

While Scioli got more votes in the first round, Marci has become the front-runner, according to polls in recent weeks that put him ahead by as many as 8 percentage points. Macri finished much better than expected, particularly in the province of Buenos Aires, which has 40 percent of Argentina's 41 million people.

Four additional candidates who ran in the first round will not be on the runoff ballot, meaning nearly 30 percent of the electorate is up for grabs.

Both men were clearly trying to reach those people Sunday, the country's first ever head-to-head candidates' debate. Five candidates participated in a debate last month before the first round. However, Scioli, at the time the front-runner, declined to participate, arguing a law was needed to regulate such contests.

Scioli changed his tune the day after the first round, challenging Macri to a debate, which was quickly accepted.

While both candidates were quick with zingers, they also both sidestepped tough questions.

Macri said if elected president, he would pressure to expel Venezuela from the South American trade bloc called Mercosur because President Nicolas Maduro had imprisoned opposition leaders.

Scioli declined to answer whether he would do the same. The topic is clearly an uncomfortable because the Fernandez administration has strengthened ties with Venezuela and Scioli doesn't want to alienate government supporters.

Scioli asked Macri why he had flip-flopped on the nationalization of the YPF oil company and Aerolineas Argentina, two popular government decisions. Macri, who opposed the moves at the time but in recent months has spoken favorably of them, didn't answer.