The Government is being warned not to cut the tax take in October's budget, in the latest forecast from the Nevin Economic Research Institute.

Researchers are urging the coalition to prioritise public capital investment and apply a modest increase to social spending instead.

Senior Researcher with the Nevin Institute, Mícheál Collins, said a possible 50-50 split in revenue and expenditure - which has been flagged in budget speculation - is not a good idea.

"It really doesn’t make sense for a government to begin to reduce the overall tax take," he said.

"Therefore, we have some concern that that's the focus of half of what the government wants to do in the budget."

He said such a view was not to say that the government could not introduce some tax cuts, but it was the scale of the planned cuts that was cause for concern.