Sinn Féin finance spokesman Pearse Doherty has described as unacceptable the length of time people have to wait for their applications for social welfare payments and appeals to be processed.
He said figures released to him indicated applicants have to wait for over a year on average for their applications for Invalidity Pensions to be processed.
Speaking on RTÉ’s Morning Ireland, he said it took 31 weeks for a Child Benefit claim to be processed.
Responding to Mr Doherty's remarks, the Department of Social Protection said it was committed to providing a quality service to all its customers.
In a statement, it said the vast majority of claims and payments were processed on time.
The statement acknowledged that in relation to new claims, while there were backlogs in certain schemes, a concerted programme of action had been implemented to tackle those backlogs.
The department said there was no backlog in Child Benefit claim processing.
It said that backlogs have been or are being eliminated in the case of the Family Income Supplement, Carer's Allowance and Disability Allowance.