Academic selection cannot be maintained in Northern Ireland without cross-party support, the BBC has learned.
The 11 plus is to be scrapped in 2008
The DUP said the government promised to maintain selection if devolution was restored to Northern Ireland.
However, with both the SDLP and Sinn Fein against its retention, this is unlikely to happen.
The DUP's Sammy Wilson, who met with Education Minister Marie Eagle on Wednesday, said the government still intends to scrap the 11-plus in 2008.
He said this would create a vacuum in Northern Ireland's education system in 2009 unless an alternative transfer test which had cross-party backing was found.
He said: "We have got to have some form of allocating youngsters to post primary school when they leave primary school.
"The big task for the assembly is going to agree what that will be.
Mr Wilson said an alternative selection system must be found
"With academic selection still being on the books, I think there will be a need for nationalists, who have been vehemently opposed to it, to work with unionists to find a form of academic selection which is acceptable so we do not have that vacuum.
"What we can't have is chaos where there is no means by which youngsters can be allocated to a post-primary school."
The government plans to scrap the current 11-plus transfer test in two years time.
However, as a concession to the DUP at the Saint Andrews talks in October, it was agreed that a new assembly could keep some form of academic selection.
The DUP has said it was told that if agreement is reached by 10 November on the deal put forward at St Andrews, the government will change the law which would have banned selection.
The Department of Education has confirmed a rewriting of the law in late November could keep academic selection, which currently uses the 11-plus transfer test to decide who should go to grammar school.
Any decision on changing the way children transfer to grammar school would then require a cross-community vote by the assembly.
Plans to scrap the 11-plus were first put in motion by Sinn Fein's Martin McGuinness when he was Education Minister and have been followed through by direct rule ministers since.