The chairman of the watchdog which monitors the public finances has reiterated his warning about using taxes on company profits to support Government spending.

Seamus Coffey, the chairman of the Irish Fiscal Advisory Council was addressing the Oireachtas Committee on Budgetary Oversight, where he said when it comes to spending plans, temporary revenues like corporation tax should be ignored.

He told politicians the Government should look at what can be relied on over a number of years.

Mr Coffey said this would be a more sustainable way of planning the country's finances, that money would be available every year not just when it comes in, such as with a corporation tax receipt.

When asked by Fianna Fáil TD John Lahart about relying on windfall taxes, the Council's Dr Martina Lawless said it is unreliable to depend on any tax. She referred to previous dependence on Stamp Duty and the construction industry driving government revenues during the building boom.

Dr Lawless told the committee when any one sector gets hit it effects total Government spending, showing how over reliance on any tax is not good.

Responding to a question from Sinn Féin's Maurice Quinlivan about how a potential no-deal Brexit could affect the country's spending, Dr Lawless said the Council endorsed warnings from the Department of Finance over a no-deal Brexit earlier this year and that the Withdrawal Agreement is still reliant on the outcome of the British election.

She said the second stage of the Brexit process is important in terms of stability, and that the negotiation for the Free Trade Agreement leaves a small but significant risk for the end of 2020. 

Labour's Joan Burton wanted to know if Ireland was in a good position in relation to Foreign Direct Investment. 

Mr Coffey said in his personal view, Ireland was in a "sweet spot" in terms of attractiveness for FDI across all areas; in investment, employment, and in tax terms. He said this was not only evident in social media companies but also in the manufacturing industries coming to Ireland.

Watch: Corporate tax - explained