Headteachers have confirmed that a boycott of national SATs exams, taken by 11-year-old primary school children in England will go ahead, two of the largest education unions said on Wednesday.
Executives from the National Union of Teachers (NUT) and the National Association of Head Teachers (NAHT) agreed to go ahead with the action after a ballot of their leadership members.
It means that their union members will not administer the Key Stage 2 (KS2) SATs exams in English and Maths, scheduled to take place in primary schools from May 10-13, the week after the general election.
Schools will remain open and the unions insisted that their members would not be on strike.
"I am very pleased that we have reached this decision," said Christine Blower, NUT general secretary.
"Not only are we boycotting SATs but we are saying to schools that this is finally the opportunity to do the exciting things you always really wanted to be doing in the classroom."
Teachers have long objected to the tests, which are used to rank schools in England as well as checking the academic progress of pupils.
They say they dominate teaching in children's final year at primary school, stifle creativity and impose unneeded stress on teachers, pupils and parents.
They want the tests replaced by teacher assessment of pupils' learning.
The tests, first introduced by the Conservatives in the 1990s, have been a key plank of the Labour government's drive to improve education standards.
The Conservatives, who would keep the KS2 tests if they win the election, say they would experiment with moving them from the last year of primary school to the first year of secondary education.
But the tests are no longer used in Wales, while Scotland does not use them for school league tables.
In England, Key Stage 3 SATs tests for secondary school children aged 14 were dropped in 2009 after delays in the previous year's marking. Science tests for 11 year-olds ended this year and have been replaced by teacher assessment.
"We cannot continue to have our colleagues and their school communities in the primary sector disparaged on the basis of a flawed testing regime," said Mick Brookes, the general secretary of the NAHT.
"We guarantee that children in Year 6 will leave with accurate information about their achievements that will be both broad and positive."