By Gary Eason
BBC News website education editor
Primary school targets are likely to be based on Sats test results
A controversial scheme under which secondary schools in England with exam results below a minimum level face closure is to be extended to primaries.
National Challenge affects secondaries where fewer than 30% of pupils get five good GCSEs including English and maths.
The "floor target" for primaries will involve the percentage of 11 year olds achieving the level expected for their age in both English and maths "Sats".
A head teachers' leader said thousands of schools could miss the target.
A spokesman for England's Department for Children, Schools and Families (DCSF) said: "We have always made it a key priority to improve all schools.
"We believe that it's right to insist on certain minimum standards in the system, because that's what parents want.
"Our role has been, and will continue to be, one of stretch and support for schools."
The DCSF is careful now to stress that it does not regard schools in its National Challenge as "failing".
But the label has dogged the scheme because Prime Minister Gordon Brown said when he launched it a year ago: "We can no longer tolerate failure."
More than 630 secondary schools were below the 30% floor target as of last year. Following this year's GCSE results, 230 of those are said to have moved above it.
Now senior managers in primary schools are being warned that they are next to face such thresholds.
Ministers have yet to announce what the floor target will be, but the head of education at the National Union of Teachers, John Bangs, is among those who think it is likely to be 65% of pupils attaining both English and maths at Level 4.
He said if ministers used the same "steamroller" approach as they had with secondary schools - in particular, ignoring Ofsted reports praising some of them - it would greatly antagonise not only teachers but parents.
"I think they really are going to get their fingers burnt," he said.
"The floor target is just patently 'one size fits all' and therefore unfair to schools in challenging circumstances."
The general secretary of the National Association of Head Teachers, Mick Brookes, also said he hoped the DCSF had learnt from "the complete mess" it had made of the announcement of the secondary scheme.
He said he thought ministers must be looking very carefully at the numbers, in determining the floor target, because they were in danger of pointing out that schools were not performing very well after 11 years of Labour government.
"If thousands - and it could be thousands, in primary - are going to be labelled as 'failing', if you like, then that does say something about the success of the government," Mr Brookes said.
Surrey County Council - one of the highest performing authorities in England - has a floor target for 2009 of at least 65%.
It says that, on the basis of their 2007 results, 39 schools - a fifth of the total - did not meet this threshold.
If that scenario was repeated nationally, more than 3,000 primary schools would be in the frame.
The head of the NASUWT teachers' union, Chris Keates, said the government should come clean on what exactly it was proposing to avoid speculation and rumour causing unnecessary stress and uncertainty to staff and parents.
Whatever its intentions, the National Challenge was now associated with a focus on failure and closure.
"Extending the rhetoric of failure to primary schools will do nothing to assist schools facing challenging circumstances," she said.
"There are some aspects of the National Challenge which could help to deliver real and lasting improvements for many primary schools.
"However, radical solutions such as closure and establishing academies will serve no purpose and must be ruled out immediately."