Speaking at a Sheffield conference on inner-city regeneration, Mr Blunkett will reveal the identity of three "pathfinders" for the initiative. Two of the academies will be in the capital, with the third in the North-west.
Mr Blunkett is also expected to say that more are planned, and give details of sponsors - up to one-fifth of start-up costs will come in cash or kind from the private, voluntary or religious sector, who will also take a role in runnng the schools.
Interest so far is thought to have come mainly from entrepreneurs such as Peter Vardy, owner of Reg Vardy Cars in the North-east, but churches are also understood to be involved in some proposals.
Academies will replace failing secondaries or provide new places in areas with a shortage.
Modelled on the city technology colleges created by the Conservatives, they will be state-maintained but independent of local authority control - although ministers have softened their stance on local authority involvement and councils are connected with each of today's proposals.