Roy Hattersley, former deputy Labour leader, will be the key speaker at the October launch of the Campaign for State Education's "Say No To Selection" drive.
CASE wants to encourage and support local groups to tackle selection, using the terms of the School Standards and Framework Act.
The Act provides for a system of petitioning and balloting to change the status of grammar schools, and allows parents to complain directly to an independent adjudicator about the admissions policies of partially selective schools.
Some schools select as much as half of their intake on ability. The Act allows schools to select up to 10 per cent of pupils by aptitude for a school specialism.
Margaret Tulloch, CASE's executive secretary, said the organisation hoped to provide a networking service for local groups.
"We're trying to support and give information and advice to anyone who's campaigning locally about ending selection - all types of selection," she said.
However, campaigners will have to wait until the formal regulations on grammar school ballots and appeals to adjudicators are issued before they can get going. That may not be until November, with adjudicators due to start work from March 1999.
The Government is opposed to any extension of selection by ability. But former schools minister Stephen Byers, in a letter to Ms Tulloch, made it clear that partial selection in areas where there is no local opposition will not be challenged.
He writes: "In these circumstances, it would be both heavy-handed and unnecessary for us to put an end to it simply on dogmatic grounds - we want to take the dogma out of education."
Mrs Tulloch added: "Despite claiming to believe that selection on ability is unfair and divisive, it seems that Government will rely on local determination and try to stand aside from these issues. There seems to be little commitment to end selection and a willingness to see an increase of selection on 'aptitude'."
Say No To Selection meets between 2.30pm and 4.30pm on Saturday, October 24 at Jeffery Hall, Institute of Education, Bedford Way, London.