Sats are too 'unreliable and stressful', say unions
National tests - Sats - for 11-year-olds in England have too high a margin of error to be used to compare schools in league tables, teachers' unions say.
The National Union of Teachers and the Association of Teachers and Lecturers say politicians and the media take the reliability of the tests "as a given".
The two unions are launching a campaign for reform of Sats, which a quarter of schools boycotted this year.
Education Secretary Michael Gove says he is committed to reviewing the tests.
The NUT and the ATL urged the government to scrap the tests for Year 6 pupils and replace them with continuous teacher assessment.
They quoted research suggesting test scores are unreliable for 30% of pupils.
Sats often meant teachers felt pressured to teach to the test and, as a result, pupils were taught a "limited and unbalanced" curriculum where learning was "shallow", the unions said.
The tests were often "stressful and demotivating" for pupils, particularly for lower achievers, while "narrowly focused" testing did not take account of the social and cultural backgrounds of pupils, the unions said.
The unions said the tests had become too "high stakes" because they were used by newspapers and websites to compile school league tables.
"They [Sats] have a high local and national profile and are subject to intense and often misinformed political scrutiny," the unions said.
"The result is that school staff, and particularly school leaders, believe that a single set of tests results might well damage or end their careers."
The statement said teacher assessment was an effective way to measure individual pupils' performance and did so in a way that promoted further learning.
General secretary of the NUT Christine Blower said the unions were not against accountability.
"Parents have an absolute right to know where their child is at," she said.
But this could be achieved more accurately and productively for learning by teacher assessment, she said.
"League tables are the serious problem - we hope we can work with the new government to make some changes in that direction.
General secretary of the ATL Mary Bousted said the intellectual arguments against Sats had already been won.
"The more you test, the more more you put perverse incentives into the scheme and you end up with teaching to the test," she said.
"Now in an inner city school where it's very hard to get good results, the rational response is to teach to the test.
"By teaching to the test, you don't help children think, or help them to connect. We want real assessment which gives real information."
Earlier this month, Mr Gove said the tests provided the public and professionals with "valuable objective data" and played a vital role in the accountability system.
He added: "I do accept there are flaws with the current testing system so I am committed to reviewing national curriculum tests [Sats] to ensure they are as rigorous as possible and in the best interests of schools, children, parents and the public.
"We want to consider what we can learn from other countries, to compare our tests with standards set elsewhere, and to look at how we can make the tests more useful."