A claim that up to one quarter of West Australian public school students achieve literacy scores at or below minimum national standards is "abject nonsense", Education Minister Peter Collier says.

Education became the political battleground on Monday, the first day of the school year, when a record 273,220 public school students went to class and attendance of pre-primary children became compulsory.

WA Opposition Leader Mark McGowan said between 16 and 25 per cent of public school students were below national literacy standards as he unveiled an $8.8 million election pledge to boost literacy rates with the reintroduction of phonics-based learning - all while dropping off his youngest child at kindergarten as part of a media "doorstop".

Mr Collier rejected Mr McGowan's assertion while talking up the Liberal government's education achievements at the opening of the Governor Stirling Senior High School at Woodbridge in Perth's east.

"That is abject nonsense - that is completely without foundation and I'm very, very sorry that they're talking down education in Western Australia," he told reporters.

Since 2008 when Premier Colin Barnett swept to power, the state had shown the nation's biggest improvement in NAPLAN literacy and numeracy test results, he said.

Last year, it spent almost $22 million on literacy programs, Mr Collier added.

He rejected the suggestion that the Governor Stirling school opening had been rushed as part of the state Liberal party's election campaign, ahead of the issue of the writ of election on Wednesday.