Fianna Fáil's finance spokesperson Michael McGrath has described the tax commitments given by the Taoiseach at the recent Fine Gael Ard Fheis as ridiculous given that we are on the cusp of Brexit.

Deputy McGrath said he did not think that people could believe a word from Fine Gael regarding tax promises, as, he said, only a few years ago Leo Varadkar was walking around with a placard favouring the abolition of the Universal Social Charge (USC).

Over the weekend the Taoiseach promised to increase the point at which people pay the top rate of tax to €50,000 for a single person and €100,000 for a two-income married couple over the next five budgets.

A single person currently pays the top rate at just over €35,000.

Deputy McGrath said the Taoiseach cannot stand over the €3 billion commitment, adding he had not stated where the money is coming from.

He said that Fianna Fail had 'set out its issues' with the plans to end the flat rate expenses scheme for tens of thousands of workers.

The decision has since been deferred until 2020.

He also said there had been no consultation with Fianna Fáil on the matter and that people should not be out of pocket where they are incurring expenses.

Confidence and supply deal talks 'going well'

Deputy McGrath has said the talks on the confidence and supply deal were going well and good progress was being made.

He said a deadline has not been set but the talks will not go on forever.

Mr McGrath said both parties are currently looking at public pay and have yet to look at areas such as transport and children.

He was speaking at the launch of his bill to ensure the Central Bank fully regulates so called vulture funds.

Varadkar says ESRI carbon tax estimate 'way off the mark'

The Taoiseach has described analysis from the Economic and Social Research Institute, which estimated that carbon taxes could cost households €3,000 by 2024 as "way off the mark".

Mr Varadkar was responding to Fianna Fáil leader Micheál Martin who said that, according to the ESRI, households currently paying €200 on carbon tax may see that rise to €3,000 per year by 2024.

He sought a trajectory of carbon taxes over the next five years from the Taoiseach.

Mr Varadkar said a trajectory had not been worked out by Government, but it was his belief that a carbon tax is necessary.

"The time will come when we are willing or ready to put forward on trajectory on carbon tax," he said.

Mr Varadkar added that it was his view that if the Government increases carbon tax, it will seek to follow the Canadian model, where money is given back in the form of tax credits and welfare.

He also called for all-party agreement on a series of carbon tax rises which would make electricity, gas, and motor fuel more expensive.

He was responding to Green Party leader Eamon Ryan.

Public service pay agreement at 'limit' of what is affordable

Separately, Mr Varadkar said the public service pay agreement is at the limit of what is affordable.

He was responding to Sinn Féin leader Mary Lou McDonald who called on the Government to engage with nurses and midwives who are "justifiably frustrated" over issues including pay, retention and recruitment.

She said a Dáil motion passed in April called for the introduction of recruitment and retention measures based on realistic proposals which prioritise pay.

Ms McDonald asked Mr Varadkar if he would "commit to acting on that motion, to engage with the unions so that nurses and health professionals get a fair deal".

In response, the Taoiseach said nurses were subject to the same pay deal as every other public servant.

"We do have a public sector pay deal, not just with nurses, but with all public servants the cost of that is €400m this year and another €400m next year ... it is about at the limits of what can be afforded."

He said this included €20m for targeted recruitment and retention, and that the State would honour that agreement.

"We are happy to engage with the nursing unions, and we will do that in the way that we have always done in the past, through the oversight group, and if necessary through the Workplace Relations Commission and the Labour Court. But we do need to remember that this is an agreement which applies to all public servants and we will honour that," he said.

Ms McDonald said the nurses have a legitimate claim and grievance and the last thing the country needed was industrial action.

The Irish Nurses and Midwives Organisation has commenced a ballot for strike action over pay.

It is recommending that its 40,000 members back a series of 24-hour strikes.

Additional Reporting Justin McCarthy & Ailbhe Conneely