Teachers have demanded that the Government upgrade pension arrangements for public servants recruited since 2013, who were placed in a new, less favourable pension scheme than their predecessors.

Teaching unions maintain that those 2013 pension reforms have caused a "substantial deterioration" in pension benefits for those taken on since that time.

However the Government is expected to strongly oppose any such pension improvements, as the reforms are forecast to save billions of euro on the public service pension bill over the coming decades.

Last December, the Government published an actuarial review showing that the State's overall accrued pension liability for current and former public servants was around €114.5 billion, which would have to be funded over the coming decades.

Public Expenditure Minister Paschal Donohoe forecast that the 2013 Single Public Service Pension Scheme would eventually reduce that liability by around 35%.

Both the old and the new schemes are defined benefit schemes which give more certainty to the employee about retirement benefits than defined contribution schemes.

However, benefits under the older scheme are based on the worker's final salary, while under the 2013 arrangements, they are calculated on the basis of career averaging.

The three teachers unions - the INTO, the ASTI and the TUI -  say members are now paying up to 17% of their earnings towards their retirement.

In a statement, the INTO noted that teachers had always paid for their pension schemes through deferred income payments to sustain them in retirement.

However, they are now paying more because the "temporary" pension-related deduction introduced during the economic crisis has been retained on a permanent basis - albeit at a slightly lower level.

In addition, because teachers take 27 years to reach the top of their pay scale, they spend less time on maximum earnings. This reduces their pension entitlements, compared to the previous pre-2013 arrangements.