The government is showing no signs of making concessions over its proposed changes to schools in England.
Ruth Kelly wants schools to benefit from outside "energy"
Education Secretary Ruth Kelly will tell a conference in Gateshead that a new generation of self-governing "trust schools" will raise standards.
She has told the BBC she can give a "categorical assurance" of no extension of selection by academic ability.
Education professionals and Labour MPs, including Deputy Prime Minister John Prescott, have criticised the plans.
On Friday, Ms Kelly is publishing a prospectus setting out exactly how the trust schools will operate with external partners such as voluntary groups, charities, universities and businesses.
She will also be giving more of an idea of who some of the likely partners will be.
She is due to speak at the annual North of England education conference, in Gateshead.
In an interview for the BBC's Ten O'Clock News on Thursday, Ms Kelly said the proposals presented "huge opportunities" for schools.
She said some two thirds of secondary schools already worked with external partners in some form.
The new trusts would make it easier and quicker for schools to take advantage of the energy that existed in their communities.
She argues that exam results have improved but there is still "a long way to go" before all children are realising their potential.
The changes "will make the biggest difference to those who need it most: to the poorest children in disadvantaged communities", she said.
Asked about possible concessions, she said she understood she had "a case to make" and would continue to set out what was - and was not - being proposed.
She stressed that Labour had legislated back in 1998 so there should be no new selection by ability.
"That's clear, but there are still people who are not convinced," she said.
Schools might have greater control over which children they admitted.
But they would still have to abide by the code on admissions which was backed by a statutory adjudicator and by co-ordinating admissions forums for each area.
"I can give a categorical assurance that trust schools won't be able to introduce selection by ability," she said.
But Ms Kelly is facing a further blow over plans to have many more independent state-funded city academies too.
A survey for the Sutton Trust education charity, by Mori, suggests most teachers are sceptical about them.
Among the representative sample of teachers in England questioned, 28% agreed academies were an appropriate way of raising standards in deprived areas - and 53% disagreed.
Majorities also disagreed that "school choice" was a reality for most parents and had improved standards, and that the current admissions system operated fairly.
The chairman of the Commons education select committee, Barry Sheerman, said: "The government should be concerned that the number of teachers who are against school choice and city academies, two key proposals, outnumber those in favour by a factor of 2:1."