A spokeswoman for the Welsh Government dismissed a suggestion that the publication of categorisation could be delayed and said scores would be revealed at the end of January.
The weightings are just one part of the new national school categorisation system and another important aspect is the assessment of a school's leadership, teaching and learning.
A union is unhappy with a Welsh schools categorisation system being introduced in January
If the Welsh Government decides to retain banding, it will mean secondary schools in Wales will be given two separate rankings as well as being subject to categorisation by education watchdog, Estyn.
Mr Hughes, secretary of ASCL Cymru, said the banding system had no future now categorisation had been hatched.
Dr Dixon, director of ATL Cymru, said: "If we keep banding then schools would be subject to the disparate judgments of Estyn, banding and categorisation which would be ludicrous.
We would much prefer to work with the department to develop the idea of categorisation, which hopefully would iron out the nonsenses produced by the banding regime and could provide much better bespoke support for schools.