The fear among education academics is that Harriet Harman's decision to send her son to a grammar school will further undermine confidence in comprehensive education.
The Government is already preparing to introduce measures that will allow popular comprehensives to become more socially selective. The latest consultation document proposes to end the ban on selecting pupils on the basis of interviews and also suggests schools be allowed to select up to 15 per cent of intake according to aptitude or ability.
The poll conducted for the Association of Teachers and Lecturers suggests there may even be a narrow majority among voters in favour of grammar schools. However, there was not a majority among the age group (33 to 45) most likely to have children in secondary schools.
According to Richard Pring, professor of education at Oxford University, the problem is that there appears to be an assumption that comprehensives are failing. "In fact, there is increasing evidence to the contrary. More pupils are leaving with qualifications and more are going into higher and further education," he says.
The reforms being promoted by the Government will, he says, bring about a return to the worst form of selection based on schools taking the children they prefer without any reference to objective criteria.
David Hargreaves, professor of education at Cambridge, who rarely sides with the prevalent orthodoxy, is also opposed to any return to grammar schools. He says the Government has not produced any convincing argument for a return to selection.
"I would have thought most schools would not want to do it. The trouble is the decision of one school to become selective has an immediate effect on other schools in the area," he says.
Professor Hargreaves believes comprehensives need to adapt by offering greater specialisation and he favours schools being able to select on the basis of aptitude.
For Ted Wragg, professor of education at Exeter, the inherent problem with increasing the choices available is that the more knowledgeable parents, that is, the middle-classes, tend to have an advantage.
"All admission systems have winners and losers and political parties need to consider who they are catering for," he says. "I would have thought, the role of Labour is to make sure the less powerful have equal access."