Argentinian Economy Minister Martin Guzman, the architect of a recent major debt deal with the International Monetary Fund (IMF), resigned unexpectedly Saturday, dealing a fresh blow to the government of President Alberto Fernandez as the country struggles with economic problems.

Guzman stepped down after a week in which Argentina’s currency hit an all-time low against the U.S. dollar amid sizzling inflation and truck drivers staging protests over shortages of diesel fuel.

Guzman, a minister since late 2019 and a close ally of President Fernandez, posted a letter on Twitter announcing his decision, adding he maintained "confidence in my vision of the path Argentina should follow."

The center-left Peronist president is facing his lowest approval rating since taking office in 2019, with cracks in his coalition, inflation running above 60%, the peso currency under growing pressure and sovereign bonds at record lows.

"I write to you to present my resignation as economy minister," Guzman said in a seven-page letter addressed to Fernandez that highlighted internal battles within the administration.

Illustrating the tensions, Guzman announced his resignation while Vice President Cristina Fernandez was giving a high-profile speech in which she lambasted the government’s economic policies. The vice president, who is not related to Argentina’s leader, is a former president herself and the governing coalition has been splintering between their allies.

The resignation leaves the ministry leaderless just as Guzman was expected to travel to Europe to negotiate a $2 billion debt deal with the Paris Club of sovereign lenders. It also deals a blow to Fernandez’s weakening power base.

"It is the chronicle of a death foretold," said Mariel Fornoni, director of the Management and Fit consultancy, adding that a painful loss in midterm elections last year for the government had hurt President Fernandez badly.

"Now he has lost another piece of his board, perhaps the most important, and is increasingly alone," she added.

Investors, already jittery about the country’s economic outlook, have pushed bonds down toward 20 cents on the dollar in recent weeks.

All eyes now will be on the replacement of Guzman, whose resignation came at the end of a week of economic turmoil.

With the Argentine peso sliding against the dollar, the government on Tuesday made it harder to acquire dollars to pay for imports as the local currency reached new lows in the parallel market used by citizens and companies to bypass official channels.

Argentina has suffered for years from a shortage of dollars, which stems partly from the distrust of Argentines in their own currency amid high inflation. Inflation is running at an annual rate of more than 60% and economists expect the rate to keep worsening.

Work stoppages by truck drivers have disrupted economic activity, including the delivery to ports of grain, which is one of Argentina’s main imports.

On Wednesday, the government said it was trying to increase the availability of diesel by allowing more biofuel to be mixed into the fuel and also by suspending the import tax on diesel.

Argentina produces diesel but not in sufficient quantities for its needs and depends on imports, with world prices rising because of disruptions by the pandemic and the Russian invasion of Ukraine.

Analysts say one of the reasons for the shortage is that it is not profitable for oil companies to import diesel because the government prevents them from charging what it costs to buy on the international market.

In his resignation letter, Guzman suggested that at least part of his reason for leaving was because he lacked political backing inside the government.

"From the experience I’ve lived," he wrote, "I consider it will be fundamental to work on a political agreement within the governing coalition so that the person who replaces me will have the centralized control of the necessary macroeconomic policy instruments ... to face the challenges ahead."

The president’s office said that it did not yet know when a replacement for Guzman would be announced. Fernandez had summoned members of his Cabinet and allies to an emergency meeting, one government source said.

"The president deeply regrets the decision but respects it. He is analyzing his next decisions," said another government source with knowledge of the matter.

Two economy ministry officials, asking not to be named, said that Guzman’s position had become untenable, especially without support for his economic agenda.

"He couldn’t continue without the tools and with (Vice President) Cristina (Fernandez de Kirchner) against him," one of the two people said. "When things are no longer possible, it is an act of responsibility to leave."

Miguel Kiguel, former secretary of finance in Argentina, told Reuters that whoever takes over will have a tough time, noting that inflation could hit 80% this year and there is a gap of nearly 100% between official and parallel exchange rates.

"We don’t know who’s coming, but this will be a very hot potato," Kiguel said. "Whoever comes is going to have a very complicated time."

Guzman had been in his post since the start of Fernandez’s government on Dec. 10, 2019, and was long one of the most high-profile figures within the Cabinet.

Early on in the administration, he was seen as a staunch ally of the president but also someone who could help bridge divides in the often-fractious governing coalition. In recent months, however, he clashed with some officials loyal to the vice president and his influence within the government appeared to be waning.

Guzman’s first challenge in the job, and success, was negotiating a restructuring of Argentina’s debt and avoiding a default.

He later reached a deal on debt relief with the IMF, but some of the more left-leaning elements of the government said it included too many concessions that would hamper Argentina’s economic growth.

Lawmakers allied with the vice president voted against the agreement with the IMF in congress and Guzman’s resignation raises doubts about whether the country will be able to meet the terms of the deal.

In his resignation letter, Guzman said that his main goal when taking the job was to "calm the economy" and in order to do that it was necessary to "resolve the problems of the unsustainable external debt that overwhelm the state, as well as all of Argentina."