A second international expert has savaged the Scottish Government after his research was cited as an inspiration for controversial primary school testing.

Professor W James Popham, from the University of California, Los Angeles (UCLA), said his work should not be construed as support for standardised assessments - particularly of five-year-olds.

He added: “Whether made from ignorance or malevolence, the attribution quotation is flat-out incorrect.”

Yesterday, Dylan Wiliam, a professor at University College London, said the use of his name in connection with the policy was a “substantial and perverse misrepresentation” of his views.

The latest attack came after the Scottish Government was asked by the Scottish Liberal Democrats to highlight individuals who supported their testing policy - particularly for five-year-olds.

The response said there was extensive research highlighting the positive benefits of diagnostic assessment and went on to cite the work of both Mr Dylan and Mr Popham.

However, Mr Popham told The Herald: “The sorts of tests typically employed in carrying out the formative assessment process are almost never standardised tests.

“Typically, those assessment devices are teacher-made classroom tests employed for the purpose of helping teachers.

“My support of the formative-assessment process should definitely not be construed as support for standardised tests and, even more definitely, not support of using standardised tests for five-year old children.”

Formative assessments help teachers judge how well a pupil is progressing while more controversial summative tests establish whether a child has reached a particular target.

The Scottish Government said officials did not intend to imply the academics supported the Scottish National Standardised Assessments (SNSA).

However, opposition parties demanded John Swinney, the Education Secretary, apologise to the Scottish Parliament.

Tavish Scott, education spokesman for the Scottish Liberal Democrats, said: “Fabricating fictional emphatic support to keep a dead policy afloat is a new low.

“Mr Swinney must immediately come to parliament and apologise for this falsehood.”

Liz Smith, education spokesman for the Scottish Conservative Party, added: “This is a classic case of the Scottish Government misusing information in order to promote a specific policy line.

“It is not acceptable and John Swinney should apologise.”

Larry Flanagan, general secretary of the Educational Institute for Scotland teaching union, also raised concerns.

He said: “Decisions should be evidence-based. On the face of it, it appears the evidence supposedly cited to support the introduction of Scottish national assessments does not stand up.”

A Scottish Government spokeswoman said the academics had been referenced as supporters of a formative approach to assessment more generally, rather than giving a specific endorsement of the Scottish National Standardised Assessments (SNSA).

She said: “In line with best practice internationally, the SNSA are designed to provide formative, diagnostic information to teachers on aspects of literacy and numeracy.”