(CNN) -- Paraguay's president is under pressure after an impeachment vote in the lower chamber of Congress on Thursday, but Fernando Lugo says he will not resign.
Lugo's presidency became endangered when a liberal party that backed him decided to join an opposition party in supporting impeachment.
The impeachment proceedings follow a June 15 incident in which police clashed with landless peasants, resulting in 17 deaths.
The document that lawmakers voted on includes nine points arguing for Lugo's impeachment, one of which was the recent clash.
The congressmen also cited insecurity, nepotism and a controversial land purchase.
The lower chamber voted in favor of impeachment by a margin of 76-1, and the issue will now go before the Paraguayan Senate. The Senate could take up debate on impeachment as early as Thursday.
Lugo said immediately after the vote that he will not offer his resignation.
"Faced with this challenge, this president announces that he is not going to resign his post and that he submits himself, fully, to the constitution and the laws to face this impeachment, with all its consequences," he said.
By refusing to resign, he is honoring the will of the people who elected him, Lugo said.
On June 15, peasants in eastern Paraguay fired on police trying to evict them from private property, initiating the deadly confrontation, local authorities and state-run media said.
The violence occurred in Curuguaty, a remote community about 240 kilometers (150 miles) northeast of the Paraguayan capital, Asuncion, near the Brazilian border.
In the immediate aftermath of the incident, Lugo replaced his interior minister and national police chief.
Four of Lugo's ministers resigned Thursday after their political party withdrew its support from the president.
Lugo could become a victim of a conflict between rural landowners and poor farmers that is a century old, said Luis Galeano, a professor at the Catholic University in the capital.
Details of the what transpired in Curuguaty remain unclear, and even if it was the police who were attacked, Paraguayans are focused on the number of dead, he said.
But the fact that Lugo lost all his support in the lower house of Congress -- only one lawmaker voted against impeachment -- is a sign that politics are at play, too, Galeano said.
The next presidential elections are not until April, but already there is a power struggle among lawmakers.
"This social conflict is being taken advantage of by the political parties," Galeano said. "The congressmen have their own interests."
It was not surprising that members of Lugo's own party voted his impeachment, he said, because they were already upset that a number of ministers he had named were from outside the party.
The impeachment is "an expression of the political process in Paraguay," Galeano said. "It's very tangled."
Lugo decided to fight the impeachment proceedings, the professor thinks, because he wants to avoid the perception that he was the only one responsible for the deadly clash.
Journalist Sanie Lopez contributed to this report.