Leading fire and police officers are to take part in parliamentary scrutiny of plans for new national forces.
MSPs will look at draft legislation, focusing on its potential impact to local democracy.
The Scottish Government's Police and Fire Reform (Scotland) Bill will establish single forces for each service by merging regional divisions.
Holyrood's Local Government and Regeneration Committee is the first to look at the Bill as it starts its passage through the Scottish Parliament.
The committee will consider what the changes will mean for councils, police boards, community planning and jobs.
The afternoon session is expected to include the president of the Association of Chief Police Officers in Scotland, the Inspector of Constabulary for Scotland and the Scottish Police Services Authority.
Representatives of the Chief Fire Officers Association Scotland and the Fire Brigades Union, as well as councillors, are also due to attend.