The Irish government faces a new crisis with the revelation that a junior minister, Trevor Sargent, has resigned after admitting he attempted to block a court case against one of his constituents.

He is the second minister in a week to resign. Defense Minister Willie O'Dea resigned after he wrongly accused another politician of running a brothel based on information he says he got from a police officer. A police investigation has been launched into both cases.

Sargent is a member of the Green Party and was formerly the leader of the party. His resignation comes as a further blow to the government, with Green Party sources now clearly very uneasy with their relationship with Fianna Fail. Some Green Party sources say the Sargent revelation may have been made by Fianna Fail members unhappy at the fact that the Greens forced the O'Dea's resignation.

According to the Evening Herald newspaper, Sargent wrote to police two years ago asking to have the charges dropped against a  constituent, Dominic McGowan, who was later convicted of threatening and abusive behavior and fined $800.

The Police Commissioner, Fachtna Murphy, has now asked local police to compile a report for him on the allegations.

Opposition politician Pat Rabbitte of the Labor Party said he was "very surprised" by the allegations.