The coalition of Opposition peers that successfully moved an amendment to the vouchers Bill on Monday may be represented as just a piece of neat political footwork, but it is sound common sense too. Of course wise management demands that experience in the four nursery pilot areas should be evaluated in the light of the first year’s operations, before vouchers are posted to eager parents all over the country.

The crucial questions are whether vouchers have guaranteed provision for all four-year-olds in the area, and whether what is now available is what parents want. Choice and diversity would be a fine thing, but more to the point is whether parents can find what they need within reach, when Pounds 1,100 vouchers won’t cover the cost of full-time provision.

Beyond that, have many reception classes lost out to competition for their four-year-olds, and has this destabilised primary school funding? Have many new private providers in fact been lured in by vouchers? How much voucher money has proved to be “deadweight” in that it has merely subsidised parents already paying private nursery fees? Has money been diverted into the four-year-old group at the expense of equally deserving three-year-olds? Nor is it known (see page 4) whether special deals in pilot authorities on distribution of the voucher money will be extended nationally.

All of these questions worry some Conservative backbenchers as well as Opposition. Labour spokesman David Blunkett is on stronger ground than the Education Secretary would like in rallying allies against the plan to reverse the Lords’ amendment in the House of Commons. It is not a fight the Government can afford to lose, but winning will not remove the questions.

Education provision for the under-fives is well-known to be fragmented, uneven and confusing, which gives it much in common with the 16-19 age-group, and may partly explain the Government’s fatal attraction to vouchers in both areas. Something to do with the pure belief in competition driving down costs held by Treasury hawks, a general ministerial desire to force LEAs out of business, and the Confederation for British Industry’s more idealistic wish to expand participation, with academic and vocational on equal terms.

But post-16 provision is even more complicated than the under-fives’, with many providers, a plurality of courses and qualifications, several funding organisations, and the fiendish difficulty of isolating 16-19 finances from that of other age-groups. A pilot voucher scheme has already been run in the form of training credits for school-leavers entering employment, who in theory could use their voucher or smart card to buy the education course and qualification they chose. But the scheme has worked out unevenly in practice. Although extended and renamed, it remains little known. A Coopers and Lybrand report produced a cool verdict on the value of a full voucher scheme That has not stopped Cabinet rumblings about sixth-form and college vouchers, and work has gone on behind the scenes to move funding across the sectors on to a more equal footing as an essential starting point. Late last year a DFEE paper reached the sweeping conclusion that comparative sixth-form and college costs were closer than had been thought. Last week a revised analysis brought the figures even more conveniently close together.

Was that because there are now many more small GM sixth forms? We don’t know because the right questions haven’t all been asked. The relevant paper draws broad-brush conclusions from available statistics, but admits frankly that few are available on the extent of cross-subsidisation - whether of school sixth forms by younger groups, or FE or TEC courses by adults or employers. Comparisons also beg value-added questions, since college students may have very different starting points from sixth-formers.

There are many arguments for more level funding arrangements post-16, apart from the need to set a voucher value, but some are in conflict with other Government policies. Mrs Shephard has promised, for example, to protect small sixth forms, but it is hard to believe that this could be compatible with a voucher scheme. Any such scheme could have a catclysmic winners-and-losers effect. This one still sounds more like manifesto material than a workable reform.