Mr Greening said Ms Blow's appointment to the government's industrial development advisory board is wrong because of the company's problems in the borough.
In a letter to Ms Hewitt, he said: 'ITNet has caused immeasurable damage to vulnerable people's lives in the areas where it has been employed to carry out
the vital service of
A spokeswoman for the firm admitted the problems in Islington, but said this should have no influence over Ms Blow's appointment.
She added: 'Bridget Blow's appointment is based on her expertise. We have had problems at Islington, but that is just one contract.'