The Labour Party has set itself a less specific target than before for the test achievements of primary school pupils in England.
The target date had already been put back two years
The existing Department for Education and Skills target is that 85% of 11-year-olds will reach the expected level in English and maths by 2006.
But Labour's new campaign policy document talks of "the overwhelming majority" being up to standard.
The target had previously included a deadline of 2004, which was not met.
The public spending agreement between the department and the Treasury also said the national curriculum "Level 4" performance of 11-year-olds - the standard expected for their age - would be sustained to 2008.
Labour's new campaign policy, launched on Thursday, said: "We will intensify the literacy and numeracy policies so that the overwhelming majority of 11-year-olds are up to standard in the basics of reading, writing and maths, with high-quality teachers and support staff in the classroom giving children more tailored learning.
"Now 77% achieve this level in literacy (up from 63% in 1997), and 74% in maths (up from 62%).
"With further concentrated effort, these proportions can rise significantly further."
The final figures for the 2004 English results showed 78% had met the expected level, rather than the 77% provisional figure.
Primary school performance did rise markedly in the late 1990s, but questions have been raised about what the results actually show.
Last month, the official statistics watchdog, the Statistics Commission, said the rising test scores had "substantially" overstated the rise in educational standards.
It said there had been only "some" rise in standards between 1995 and 2000.