Nearly two thirds of education directors and their deputies would refuse to report to a social services director under the government's proposed merger of education and child social services.
LGC's second survey of the impact of the children's green paper found 74% of respondents support the merger, but with strong qualifications.
This raises the prospect of a tussle between the two professions over which would take the top post in the merged structure.
One respondent said: 'Absolutely, categorically not. I would resign first.'
Another said: 'Education officers take an instant dislike to social workers because it saves time.'
Andrew Cozens, president of the Association of Directors of Social Services, said: 'It reflects concerns about professional issues in delivering the government's agenda.
'But the pattern in local government has been for people from many backgrounds to rise into senior management.'
One senior figure speculated that since a director of children's services would control about 80% of most councils' budget, the position of the chief executive would be under threat. Chief executives might therefore name themselves as directors, leaving separate education and social services teams intact below them.
Education chiefs were more optimistic about whether the services would merge well, with 65% taking this view against only 25% of social services directors (LGC, 24 October).
The government's plan requires a lead councillor and director for children's services. It expects, but does not require, combined children's departments with adult social services split off.
Replies showed that one third of councils had already divided services.