A Northern Ireland minister has banned officials from the Republic sitting on committees advising his department.
Despite the long-standing cross-Border co-operation on green issues, DUP Environment Minister Sammy Wilson refused to renew the appointment of one leading environmentalist from the South and is expected to cull others from his advisory committees.
It is understood officials from the Republic serving on Historic Monuments Council and the Historic Buildings Council may also be told their terms in office will not be renewed.
Mr Wilson said he did not need advisers from outside Northern Ireland to work on internal policy issues, but he has been accused of using his office to score political points.
The North's Department of Environment (DoE) confirmed that Patrick Warner, a divisional manager in the Republic's National Parks and Wildlife Service, was told he would not be reappointed to the Council for Nature Conservation and the Countryside when his three- year term ends in February.
A DoE spokesman said: "Mr Warner was appointed by the DoE minister during direct rule. We now have a new regime.
"We have devolution. The minister feels people from Northern Ireland should be serving on boards relating to Northern Ireland."
The move comes as the DUP and Sinn Fein are at loggerheads over a series of issues, causing increasing disruption to the work of the Assembly.
The chair of the Assembly's environment committee, Patsy McGlone, of the SDLP, hit out at Mr Wilson's move.
"This is a classic case of a minister using his office to score a DUP point," he said, adding that cross-Border co-operation was vital to many important areas of DoE work
Sinn Fein environment spokesman Daithi McKay said the move was "petty".