Policy differences between England and Wales are hampering the provision of health, transport and higher education services, according to MPs.
Committee chairman Dr Hywel Francis said: “We warmly welcome the progress which has been made since our original reports.
“Better communication between Wales and Whitehall is clearly taking place in a number of key areas where previously it was lacking.
“However, we continue to have serious concerns about particular issues where deficiencies remain. The relevant UK government departments must address our concerns and take action to ensure people crossing the Welsh-English border do not receive a lower level of service.”