More than 100 Labour MPs are expected to support the Comprehensive Future campaign which aims to push a third-term Blair government into abolishing the remaining 164 grammar schools in England.
Campaigners hope to win the support of the Labour policy commission drawing up the manifesto. They hope responses to the consultation will strengthen their case. But, though the consultation document will refer to the need for social equality in education, it ducks the question of the future of selective schools.
Labour leaders hope the exercise will show they are listening to the public and encourage teachers to join the debate. They believe responses will support their view that more, not less, change is needed in education.
Key areas for debate include reform of the 14-19 curriculum, how to give heads more freedom and ways to broaden the primary curriculum while boosting literacy and numeracy.
David Chaytor, MP for Bury South and a leading member of Comprehensive Future, said there was growing support among the policy commission for an end to selection.
Charles Clarke reopened the debate on the future of grammars shortly after becoming Education Secretary last year. But the Prime Minister's inner circle is anxious to avoid a battle with supporters of selective schools.
It fears that any move against grammars will be perceived as an attack on excellence.
In 1998, Tony Blair's Government introduced rules allowing parents to decide whether to axe grammar schools in their area. So far, the only ballot to take place is in Ripon, Yorkshire, where parents voted overwhelmingly to preserve the status quo. Opponents of selection argue the rules are unfair and designed to prevent ballots taking place.
Last week when 126 Labour MPs voted for a 10-minute rule Bill that would scrap area ballots and force ministers to canvass the views of all schools on the future of grammars. But, although the Bill won a second reading, it has no chance of becoming law.