The key stage 2 Sats reading paper has been released early after complaints from parents and teachers over the difficulty of the questions.
Due to be published on Monday, the Standards and Testing Agency (STA) made the exam sat by Year 6 pupils last week available “due to public interest in the tests”.
James Bowen, assistant general secretary at the NAHT school leaders’ union, said: “We are pleased that the government will be looking at what happened with the reading test this year.
“We have had clear feedback from school leaders that this year’s paper was not pitched appropriately for a large proportion of pupils and even highly proficient readers struggled with it.
“It is essential that test papers are accessible for the large majority of pupils. We need to remember that these are 10- and 11-year-olds and the last thing we need are papers that leave them feeling demotivated and dejected.”
Last week, the NAHT expressed concerns over the Sats reading paper, saying it planned to raise the issue with exams regulator Ofqual and the STA.
In the test, children had one hour to answer 38 questions about three set texts.
The first was an extract from a story about friends who believed they had come across sheep “rustlers” - a word used in the text, which means someone who steals animals from farms.
The second was an interview with a bat expert about a bat colony in Texas, adapted from a 2016 New York Times article.
The final passage was taken from a book called The Rise Of Wolves, where a young boy called Innis hears a wolf in the remote rural area he lives in.
Earlier this week, schools minister Nick Gibb said he would be looking at this year’s KS2 Sats reading paper following reports that it left pupils in tears.
A Department for Education spokesperson said: “KS2 assessments are an important way of identifying pupils’ strengths and where they may have fallen behind as they head to secondary school.
“The STA independently develop these tests, with questions rigorously trialled with Year 6 pupils and reviewed by education and inclusion experts to ensure appropriateness. Ofqual regulate all national curriculum assessments, which includes observing STA’s processes.