What's not black and white but readiness all over? That would be Massachusetts Governor Deval Patrick?s proposal for a new breed?or at least brand?of school in the Bay State.

The outline of Patrick?s so-called "readiness schools" may be hard to make out, yet this much is clear: in proposing them Mr. Patrick is stepping out on a cliff, challenging the preferences of the statewide teachers unions, which helped get him elected in 2006.

Six months after his 2006 election, the governor convened the "Readiness Project" of more than 200 leaders and experts to suggest ways to overhaul the state?s public education system. One idea that emerged was to create schools that would adopt the best characteristics of both charter schools and regular public schools run by districts.

Like charters, they could be freed of many of the constraints on regular schools, including common provisions found in teachers' union contracts. If teachers at one of the new schools did choose to unionize, according to Paul Sagan, who was on the leadership council for the project, collective bargaining could extend only to wages, benefits, and due process procedures related to dismissal.

Like regular schools, the "readiness" schools would be accountable to school districts and receive funding through them.

Massachusetts currently has the maximum number of charter schools allowed under its cap, some 65. Boston has another 20 charter-like ?pilot??? schools, the result of an agreement struck between the local teachers union and city and school officials. The schools typically hire nonunion teachers, and the unions have criticized charter schools.

Yet the leaders of both state teachers unions, one an affiliate of the National Education Association and the other of the American Federation of Teachers, said they were "open" to the proposal. Likely translation: It gives them a headache, but the prospect of a public rift with the Democratic governor is even more disturbing.