Guatemala's once-powerful vice president has quit amid a customs corruption scandal that has implicated her former private secretary.
In a letter, Roxana Baldetti said the move meant she was giving up her immunity from possible prosecution and promised "to collaborate with all investigations". She has denied any involvement in the alleged bribery.
President Oscar Perez Molina called the decision "brave" and said it was her own. MPs voted 149-0 at a special session to accept her stepping down.
Ms Baldetti is the first Guatemalan vice president to step down due to a corruption case, although prosecutors have not implicated her in the scandal.
The resignation shows the continuing impact of a United Nattions commission that has been investigating criminal networks and fighting impunity in Guatemala since 2007. It worked with prosecutors who brought charges in the customs case.
Ms Baldetti's former aide Juan Carlos Monzon Rojas is alleged to have been the ringleader of a scheme to defraud the state of millions of dollars by taking bribes in exchange for lower customs duties.
His last known whereabouts were overseas and he is currently being sought by authorities.
Recent days had seen rising calls for Ms Baldetti's resignation by protesters and influential business leaders. The country's Constitutional Court ruled that congress would have the power to strip her of the immunity from prosecution that came with her office.
After the announcement of her resignation, hundreds of people celebrated in the streets of the capital Guatemala City, letting off firecrackers and honking horns.
"Roxana's resignation is a victory for the people!" jubilant protesters chanted in Constitution Square and thousands more turned out for another celebratory rally.
Former journalist and businesswoman Ms Baldetti was one of the founders of Mr Perez Molina's conservative Patriotic Party in 2001, served as head of its congressional delegation and was its secretary general until earlier this year.
Her resignation adds to disarray for the governing party ahead of the September 6 elections. Its presidential candidate, Alejandro Sinibaldi, quit the party last month, complaining of corruption and of feuds with Ms Baldetti. Mr Perez Molina's approval ratings have been plummeting.
Mr Perez Molina said he would send congress a list of three names from which a new vice president could be selected.
At least 50 private citizens and public officials, including Guatemala's current and former tax chiefs, are suspects in the customs scandal. Prosecutors said 27 were in custody.
On Friday authorities arrested five lawyers who allegedly bribed a judge to free suspects jailed in connection with the case.
Prosecutors and a UN investigative commission said the lawyers paid Judge Marta Sierra Stalling to release the three suspects on bail.
Authorities revoked bail and were seeking to lift Judge Sierra Stalling's judicial immunity in order to launch an investigation.
In Washington, US State Department spokesman Jeff Rathke expressed support for Mr Perez Molina's "efforts to address charges of official corruption in Guatemala", as well as the UN panel known as the International Commission against Impunity in Guatemala.