David Blunkett’s attempt to give homework the Labour party’s official stamp of approval has received a lukewarm response from teacher associations and unions.

They objected that in extolling the virtues of homework, the shadow education secretary was merely stating the obvious and said prescribing the precise amount of time children should spend on it amounted to interference. And they claimed that the vast majority of schools were already setting his recommended level of homework or more.

Mr Blunkett’s proposal of half-an-hour homework for primary pupils every night and 90 minutes for secondary students is being widely interpreted as an attempt to snatch the traditionalist agenda back from Gillian Shephard, whose appointment of a steering group on spoken English to declare war on the “grunters” was announced at the Tory party conference.

It has also been pointed out that the issue of homework highlights inequalities in education - if homework is so important, the child who can work in privacy and comfort with supportive parents is in a very different position from the one in an crowded council flat with the television on.

John Sutton, general secretary of the Secondary Heads Association, said: “This is the core issue; the availability of a quiet room at home is one of the main things that marks out the difference between pupils. There are also issues for teachers - if 20 per cent of the pupils have not done the work, possibly for good reasons, does the teacher show them up in front of the class the next day, or quietly glide over it? If the latter, what sort of message does that convey to the rest of the class? I think Mr Blunkett is being a tad simplistic. ”

Mr Blunkett’s comments were made during a speech to the annual conference of the Association of Metropolitan Authorities in Wakefield last Friday, in which he lamented the creation of a “voyeur generation” who watched TV rather than “reading, conversing and imagining”.

After recommending that primary pupils should spend half an hour a night on homework and secondary pupils 90 minutes, he pointed to several successful examples of after-school study centres and homework clubs across the country, such as the “study support centres” in Liverpool funded partly by the Prince’s Trust.

The problem for the Labour party is that every child would have to have access to such facilities if disadvantage at home were to be overcome, and this would cost.

A spokesman for the Labour party preferred to portray the proposal as a means of highlighting the role of parents and encouraging local education authorities to think about study centres.

Both Mr Sutton and John Kenward, chair of the curriculum committee at the National Association of Head Teachers, said it was very rare for a school in England and Wales not to have a homework policy. “At secondary level,” said Mr Kenward, “the amount of homework ranges from one hour to three or more. ”

A report published by the Office for Standards in Education in June came to broadly favourable conclusions about the state of homework in primary and secondary schools: most of them set it, and the majority of secondaries and a quarter of primaries have a written policy on it.

Among the teacher unions, only Nigel de Gruchy, general secretary of the National Association of Schoolmasters Union of Women Teachers, condemned Mr Blunkett’s proposal outright. Doug McAvoy, general secretary of the National Union of Teachers, said that guidelines on the role parents could play would help, but resisted prescription of amounts of homework, while Peter Smith of the Association of Teachers and Lecturers warned Mr Blunkett that “the public will not support a new initiative if they interpret it as another call for already overstretched parents to work harder”.

Meanwhile homework appears to be a high priority in Scotland - Strathclyde region invested Pounds 1.5 million this year to help schools establish study support centres in 150 schools along the lines praised by Mr Blunkett and every Scottish school receives guidelines and the latest research from its local education authority.