Brexit’s impact on Welsh ports will be discussed when assembly members meet Irish politicians and businesses.
Monday’s Dublin meeting is part of an assembly External Affairs Committee inquiry and is on the day the UK begins the process of leaving the EU.
The fear is a “soft” post-Brexit border between Northern Ireland and Ireland could result in more stringent controls at Welsh ports for freight operators.
First Minister Carwyn Jones has warned that could mean job losses.
The Irish Minister for Transport, Tourism and Sport, Patrick O’Donovan, and representatives from the Irish Exporters Association are among those who will be meeting AMs during the Dublin visit.
The UK’s formal Brexit negotiations with the European Commission are due to start on Monday in Brussels.
Launching a paper on Brexit and Devolution last week, Mr Jones said the question of Ireland was “insoluble” at the moment.
He said Wales had an interest in the border between the north and south of Ireland because of Wales’ maritime border with the Republic.
Mr Jones warned a “seamless” border between north and south, twinned with customs checks at Welsh ports could provide an incentive for trade to avoid Welsh ports.
Freight operators could “go through Cairnryan in Scotland, go through Liverpool an go to Northern Ireland then down rather than mess about in Holyhead, Fishguard and Pembroke”, he warned.
“So there are job losses there if we’re not careful”.
The first Minister said the Welsh government is working with the Irish government on the issue.