Brexit is set to top the agenda for the Fianna Fáil's 79th Ard Fheis on Saturday.

The gathering takes place at the Citywest Hotel.

Also on the agenda is justice, housing, health and climate change.

It comes as the party faces growing unrest from grass-roots members over the decision to continue supporting the Government.

While SDLP leader Colum Eastwood will also address the conference, following the partnership announced between the two parties last month.

The two parties have called on pro-remain parties across Ireland to form a Brexit alliance.

SDLP's Colm Eastwood (left) and Fianna Fáil leader Micheal Martin in Belfast in January | Image: Supplied

Party leaders Micheal Martin and Colum Eastwood have set out five core principles for parties across the island to agree on.

"The arithmetic in Westminster no longer allows us to leave anything to chance", they said in a joint statement on Thursday.

"Brexit can only be stopped by actions, not words or placards. Extraordinary times call for more than ordinary measures.

"Together, pro-remain parties must agree and act upon a set of principles that ensure the protection of people across this island, from Derry to Cork.

"Together, the SDLP and Fianna Fáil agree that all pro-remain parties must recognise and invoke five core principles necessary to stave off the worst outcomes of Brexit".

Speaking ahead of the Ard Fheis, Mr Martin said Brexit is more important than collapsing the Government.

"Brexit is probably the severest threat in over a decade to Irish society.

"It fundamentally changes the order of economic relationships between Britain and Europe and Britain and Ireland for the first time in 50 years.

"The agri-food industry has been into us, and into the Government, saying it's really armageddon for them and for the beef sector".

Mr Martin will deliver a keynote speech to delegates later on Saturday evening.