The Minister for Education has said that he will announce a comprehensive set of measures soon to deal with a shortage of teachers in certain subject areas.

Richard Bruton was speaking during a Dáil debate on a Fianna Fáil private members' motion highlighting teacher shortages.

He accepted that the Government needs to improve its performance in the recruitment of science, home economics and Irish teachers.

Mr Bruton said that retired teachers can be used to provide substitution where gaps arise, many of whom retire before the age of 60.

Fianna Fáil's education spokesman Thomas Byrne said there is a crisis in teacher recruitment.

He said this was a problem that had been denied and, as a result, no action is happening.

Sinn Féin's education spokeswoman Kathleen Function said her party is supporting the motion and that, for her, pay inequality is the key issue causing teacher shortages.

She said there is such a disparity between teachers' pay, that it is a huge contributing factor to the teacher shortage crisis.

Newly qualified teachers are on a lot lower pay than their colleagues and cannot afford houses so the option of going abroad is more attractive to graduates, Ms Function said.

She said that unless the issue of pay inequality is addressed we cannot address the teacher shortage which is coming to a "crisis point."

She said that substitute teachers are filling in who do not have the necessary qualifications and that is "not adequate."

Earlier, during Leaders' Questions, Fianna Fáil leader Micheál Martin said that second level schools are finding it hard to recruit teachers and that an "urgent intervention" is needed.

"Overall applications to become second level teachers have dropped from 3,000 in 2011, to just 1,000 in 2017 with only 600 applications this month," he said.

Mr Martin said the cost of becoming a teacher is too expensive and that an "urgent intervention" was needed.

"Post graduate programmes have become the cash cow of university because of the neglect of funding on the part of the government" he said.

Taoiseach Leo Varadkar defended the Government's approach to teacher recruitment and said a drop in the number of applicants for teacher training courses was related to cyclical trends.

He said: "When the private sector is going well and economy is going well, lots more people gravitate towards courses like ICT, business, architecture because that's where there are enormous opportunities.

"When the economy is going less well, CAO applications tend to go much more towards public sector jobs because they are more secure and you are more likely to get a job when there are layoffs in the private sector, and that's to be expected."

Mr Varadkar also said the Government is engaged with unions about a pathway to restore and equalise the starting pay of new entrants.

Last November, the country’s three main teacher unions said they believed that pay inequality in the sector was causing a "crisis" in teacher recruitment and retention.

In a joint statement the presidents of the TUI, the INTO, and the ASTI called for an acceleration of the process of pay restoration for teachers employed since 2011.

They said the emerging crisis had seen a sharp fall in applications to teacher education courses, as well as an increase in emigration among recently qualified teachers, and led to increasing difficulties in filling posts and employing substitute teachers.