Economic think-tank the ESRI says the cost of implementing the government's tax plans could cost 750 million euro.

The ESRI has released an analysis of the government's proposals outlined in the Spring economic statement.

The coalition says it has 1.5 billion euro more in the state's coffers than it expected.

But the ESRI says almost half of this will be spent if the government pursues plans to keep welfare payments in pace with inflation and reduce the Universal Social Charge.

Tim Callan is a Resarch Professor with the ESRI: