The Taoiseach has asked all Ministers of State to resign so that he can reappoint a reduced number of them later this month.
It is thought he is likely to appoint 15 or 16 ministers.
In a statement, the Department of the Taoiseach said it was agreed at a Cabinet meeting this morning that there is a need to restructure the way that Government does its business.
This is to ensure 'the Government is more effective and delivers best value to the taxpayer'.
The Taoiseach will re-examine the roles and functions of Ministers of State before making his appointments.
Mr Cowen met with the current junior ministers today to discuss this with them.