The revolutionary proposal to throw open the door for all schools to select pupils on any criteria they choose seems to be based on the Government’s evaluation of Labour’s vulnerability over the selection issue after Harriet Harman’s political faux pas.

Gillian Shephard’s speech at the Institute of Education last week revealed that the Tories are staking everything on this weakness, and hoping that nostalgia for grammar schools will be powerful enough to persuade voters to endorse a wholesale revival.

The speech left her audience of educationists stunned - it seemed from the tentative questioning afterwards that few had been able to digest its radical implications.

While she stopped short of recommending a return to the 11-plus, she said: “We think all schools should consider what sort of admission policy will best match the needs of their local communities . . . where a school wants to introduce a greater degree of selection, because it believes it can provide a better education for its pupils by doing so, we want it to have that choice.” No type of school is excluded, no form of selection is ruled out, and no limit is put on the number of selected pupils.

This should be seen, as Mrs Shephard admitted, as a manifesto pledge rather than a herald of legislation - a White Paper will outline the detail in June. The speech was also intended to squash persistent speculation about a rift between Mrs Shephard and John Major on education policy.

Cultivating an appearance of unity is obviously important, especially since a MORI poll last week found that the number of voters who think the Tories are divided has jumped from 14 per cent in 1991 to 48 per cent, but some thought she protested too much - David Hart, of the National Association of Head Teachers, said that her protestations made him “deeply suspicious”.

Mrs Shephard returned to this theme several times. She and John Major are “absolutely united on this [selection] and other education policies,” she insisted afterwards.

She also stressed that her relationship with the chief inspector, Chris Woodhead, was a model of harmony: “I am not at war with him,” she said, adding - in a change to the text of her speech - “I am at one with him.”

But the speech, taken as a whole, tended to reinforce the view that there are two Gillian Shephards. She began by making some general points about the contradictory prejudices and class attitudes that permeate British society - anti-intellectualism and anti-vocationalism. People still tend to divide humanity into “those entitled to dream dreams and see visions while an army of hewers of wood and drawers of water attend to their every need”. This, she says, is “a dangerously prehistoric attitude”.

She went on to warn against the tendency to judge the present situation in education using “the intellectual baggage of our own experience”. It is tempting, she said, “to look back with yearning to a golden era and sometimes to believe that if we put the clock back we would find it again . . . in fact of course it never existed.” She then launched into a potted history of the Government’s achievements.

Where all this leaves the Labour party will depend on whether voters are beguiled by the populist appeal of a grammar school in every town (having forgotten secondary moderns) or whether the introduction of a sea of clear blue water leaves more of the middle ground for Labour to colonise.

Labour dismisses the Education and Employment Secretary’s plans as an irrelevance. Gillian Shephard, said a spokesman for David Blunkett, has given the appearance of capitulating to the extremists in John Major’s Policy Unit for the sake of unity, although she knows very well that there is little demand for a large-scale return to selection among schools.

During the consultation on the Government’s previous proposal to allow 15 per cent selection, only 15 out of 1,500 organisations said they were in favour. Labour policy adviser Michael Barber said that the Government’s lurch to the right leaves Labour in a generally stronger position - the task now will be to draw attention to the disadvantages implied by a return to selection while emphasising Labour’s commitment to the territory formerly claimed by the Conservatives - standards, diversity and specialist schools.

Margaret Tulloch, secretary of the Campaign for State Education, said she thought that the only votes the Tories would win on grammar schools would be those of the over- 50s.

She was, however, concerned that constant press reports about plummeting standards were hitting home: “In poll after poll, most parent say they are happy with their children’s schools although they think the nation’s schools are a problem.”

Schools themselves sounded baffled by the Government’s agenda. Not one of the heads contacted by The TES (all from schools identified by the Office for Standards in Education as excellent or good and improving) said they would be tempted to introduce selection either by academic ability or aptitude in a particular subject.

Katie Rush, head of Brook Vale high school in Leicestershire, said that the hot issue among heads was the budget: “We’re not sitting around rubbing our hands gleefully thinking how can we get the top 15 per cent of pupils in our area.”

Peter Crook, head of the oversubscribed St Peter’s Collegiate School in Wolverhampton - a voluntary aided school that selects on religious background - said that although his school was a technology college, “we don’t select on aptitude for technology”.

He said that increasing selection might be attractive to those schools that wanted an easier life, particularly in inner cities: “If in Wolverhampton one or two schools broke ranks and went selective in this particular catchment area, the whole pack of cards would collapse - we’d become a sink school. It’s my greatest fear.”