Peru's government poised to quit
Mr del Castillo said the president would decide his future.
Peruvian cabinet ministers are poised to tender their resignation to the country's president over an alleged scandal over oil concessions.
Prime Minister Jorge del Castillo said that he and his cabinet were ready to put their fate in the hands of President Alan Garcia Perez.
The move follows a frustrated attempt by the cabinet to explain its decisions before parliament.
Congress is to investigate alleged bribe-taking by politicians.
On Sunday, a TV station broadcast a tape which it claimed was a recording of an executive in the state oil company, Petroperu, and a prominent lobbyist discussing payments to help Norwegian oil company win contracts.
The company, Discover, which was awarded contracts to explore oil in Peru, denies the allegations.
Mr Garcia has ordered an investigation and insisted that the government must be purged of corruption.
The minister have denied the allegations but there have been strong calls across the political spectrum for the Mr del Castillo's resignation.
Energy and Mines Minister Juan Valdivia has already resigned.
Petroperu's president, Cesar Gutierrez, has also resigned, although he has denied any involvement in the scandal.
Mr del Castillo appeared before Congress earlier on Thursday, flanked by all the members of his cabinet, but was not allowed to speak as Congress has moved for a motion of impeachment against him.
Afterwards, Mr del Castillo told a press conference that he and his cabinet were "going to the presidential palace to offer our posts to the president so he can decide".
This week, thousands of people protested in several Peruvian cities, calling for the government to step down.
They accused the governing party Apra of "stealing" while the people were struggling.
The BBC's Dan Collyns in Lima said there appears to be a web of corruption surrounding multi-billion dollar deals over land for oil and gas exploration in Peru.