The Ombudsman for Children has written party leaders involved in government formation talks to express concern over the potential abolition of the Department of Children and Youth Affairs.

It is the second time that Dr Niall Muldoon has written to the Taoiseach Leo Varadkar, the leader of Fianna Fáil Micheál Martin and the leader of the Green Party Eamon Ryan about the issue.

The ombudsman says abolition of the Department would be inconsistent with the State's recognition of the importance of vindicating children's rights - illustrated by the inclusion of Article 42A in the Constitution. 

He says it would be contrary to recommendations made by the UN Committee on the Rights of the Child in 2016 and regarded as a regressive measure by the committee.

Dr Muldoon says it would also result in "reduced visibility of children" at a time when his office continues to receive serious complaints from children and young people in Ireland.

He points out that the establishment of the DCYA in 2011 and of the Minister for Children and Youth Affairs as a senior ministerial role occurred against the backdrop of reports that illustrated the State's shameful treatment of children over many decades. 

He also says there does not appear to have been a rigorous risk assessment to evaluate the potential impact of the loss of the Department.

In his letter to the three leaders, Dr Muldoon has warned that abolition of the Department "would have a damaging effect on children's rights and welfare".

He expresses "grave concerns as to what this could mean for children", particularly the most vulnerable.

Dr Muldoon told RTÉ's Today with Sarah McInerney that "there has been more talk about cattle than children" during the government formation talks, aside from talks about abolishing the Deparment.

He said "it is really concerning that children are not at the centre of that" when just months ago politicians were all praising the work of children on climate change in the Dáil.

He said eradicating homelessness, changing direct provision and focusing on children's mental health are the priorities he wants to see the next government focus on, and has written to the parties outlining those issues.

Dr Muldoon said that after 100 years of abuse and neglect of children, of ignoring them and dismissing their voices, there remains serious work to be done and the Government need to continue and grow the Department.

He said the focus on children will fall down an agenda if the portfolio is consumed into the education department.

He added that he has been waiting three years for a children's waiting list for health services, and it shows that children are not a focus in individual departments, and therefore need a standalone Cabinet portfolio.