Primary care has been undermined and hospital waits could rise because of NHS reorganisations in Wales and Northern Ireland, GP leaders say.
Merging Northern Ireland's four health boards into one has 'decimated' support for primary care, GPC Northern Ireland chairman Dr Brian Dunn said.
'People with invaluable experience have been retired, and new staffing arrangements are wholly unrealistic.'
The overhaul has also left just '0.4 whole-time equivalent staff' to manage revalidation for more than 1,000 GPs in Northern Ireland, Dr Dunn said.
In Wales, reorganising 22 local health boards (LHBs) into seven has left GPC Wales with 'no confidence that the GMS contract will be run correctly'.
GPC Wales chairman Dr David Bailey said concerns in Northern Ireland mirrored those in Wales. 'The key issue is that at the very top level there is no one charged with looking out for primary care. We do not know what the new boards will look like yet and they are supposed to be kicking off in October.'
Dr Dunn warned that waiting lists in Northern Ireland may rise because five commissioning groups set up in the reorganisation are unlikely to function 'in the foreseeable future'.
'There is effectively no primary care commissioning in Northern Ireland. Waiting lists are going to start going up again.'
Dr Bailey said GPC Wales had called for key NHS services with experience of managing GP contracts to be maintained, but had not yet received assurances from the Welsh government.
A spokeswoman for the Northern Ireland health department said the changes should eventually strengthen primary care. The Welsh health department did not respond.