This week, 11 year olds will be taking national tests in schools in England
An over-pressured school testing regime in England is under fire from MPs, as hundreds of thousands of 11-year-olds begin taking their "Sats" tests.
Barry Sheerman, who chairs the Commons schools select committee which has investigated the issue, sees "something wrong" in the amount of testing.
He also told the BBC's Panorama that the proposed replacement, single level tests, may make the problem worse.
Schools Minister Jim Knight said the tests helped to raise standards.
The testing regime in England, with its national tests and school league tables, seems set to face further criticism from the committee of MPs, when its report is published on Tuesday.
"There's something wrong with the amount of testing and assessment we're doing, the quality of testing and assessment we're doing, and the unseen consequences of that testing for the whole school culture," said Mr Sheerman.
Barry Sheerman casts doubt on the proposed replacement for Sats
"It is still a culture where the success of a child, of a teacher, of a school is linked to testing, testing, testing, that is the problem," he told the BBC's Panorama programme, Tested to Destruction.
But Mr Sheerman also raised doubts over a possible replacement for the tests - "single level tests" - in which pupils would be assessed when their teachers thought they were ready.
Rather than lifting the burden of testing, he warned that they could make it "ever present in the atmosphere of a school".
There have been many complaints from teachers' organisations about the national tests, introduced by the previous Conservative government and retained by Labour when it entered office in 1997.
This spring brought claims of over-testing and pupil stress from several teachers' unions.
Reflecting such opposition to the Sats tests, Frank Bunting, a teacher from Phoenix Primary School, Liverpool, said: "I dislike them. I resent them. But more than anything else I resent the league tables that go with them."
But the government has defended the importance of tests as part of the drive to raise standards. It has argued that testing and accountability in league tables are a valuable way of measuring the progress of schools and the education system.
"Sats are there to give pupils an understanding of how they're doing nationally, to give parents the opportunity to see how well their child is doing and how well the school is doing, and for the public to see how well schools generally and how the school system as a whole is performing," says Schools Minister Jim Knight.
"The standards in our schools are rising, and part of the reasons for that are tests and tables."
In Wales, where the Sats tests have been scrapped, the education minister says teachers now can be more "productive", without the need to focus on the test results.
"In terms of the evidence it was quite clear that we had to enable our teachers to be able to be free of the 'teach to test' culture - that of course we knew wasn't effective, wasn't enabling our teachers to be productive in the classroom," says the Welsh Assembly Government's Education Minister, Jane Hutt.
Panorama: Tested to Destruction is on Monday 12 May at 2030BST on BBC One.
Children drew monsters when they were asked to visualise Sats tests.
Panorama: Tested to Destruction, BBC One Monday 12 May 2008 at 8.30pm.
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