The transfer test will be gone within two years, Sinn Fein's Martin McGuinness has insisted.
Martin McGuinness (right) was the last Stormont education minister
The DUP claimed after last week's St Andrews agreement that they had secured the future of academic selection.
But the former education minister who began moves in 2002 to scrap the test, said this was wrong and any assembly must find a suitable alternative.
"If we work together, we can put in place a process to strengthen rather than weaken our education system."
Mr McGuinness said people were "too hung up on this business of academic selection".
The DUP said they were told that if agreement is reached by 10 November on the St Andrews deal, the government will change the law which would have banned selection.
Any decision on changing the way children transfer to grammar school would then require a cross-community vote by the assembly.
The DUP said they have secured the future of grammar schools
On Friday, the DUP's education spokesman, Sammy Wilson, said that was unlikely to happen since nationalists and unionists have opposing views on selection and were unlikely to agree to scrap it.
Nationalist parties are in favour of scrapping selection.
Northern Ireland Secretary Peter Hain had already promised to give the Assembly a veto on the changes if devolution was fully restored by the government's previous deadline of 24 November.
As assembly education minister, Mr McGuinness made the first move to end the current system hours before he left office in October 2002 when devolution was suspended.
The last transfer test is scheduled to be held in 2008.
Last December, the direct rule education minister at the time, Angela Smith, said that by 2009, schools could take pupils based on a flexible "menu of criteria".