Heather DuQuesnay, the new SEO president, said they would do it "not because we are oblivious to the slights of central government, nor because we are their lackeys - but because we are committed to promoting the good of the communities we serve and because parents' and children's needs will always be paramount".
She said little had been done to assuage concern and outrage among local government to the scheme which will give parents vouchers worth Pounds 1,100.
In her presidential speech Mrs DuQuesnay spoke of a "wounded sense of disbelief" that the readiness of local coucils to extend and develop early-years services could be ignored.
Many councils - like Hertfordshire where she is education director - were already looking to work with the private sector on early-years provision.
While councillors had total confidence in the quality of local education authority provision, they were now concerned that the viability of a nursery class or school could be undermined by the loss of a handful of voucher-bearing pupils.
"They are also concerned that parents who are disorganised, illiterate or disadvantaged may never get to grips with their voucher at all."