Tánaiste Leo Varadkar has said he believes new changes to collective bargaining rules may end up being challenged in the courts.

The Government has published a plan that would see non-union employers facing penalties for failing to negotiate with trade unions.

The recommendation is contained in the final report of a high-level working group that was set up to review collective bargaining and the industrial relations landscape in Ireland.

It comes ahead of a new EU directive which will require member states to facilitate much greater collective bargaining.

The report says there should be "good faith engagement" between employers and unions.

Under the proposal, if a union represents 10% or more of a grade, group or category within a company, the employer will be obliged to engage in good faith with the union and can been ordered to do so by the Circuit Court.

"Failure to comply with such an order of the Circuit Court is an offence and a person guilty of such an offence will be subject to a pecuniary penalty," the report states.

Speaking today at the Industrial Relations News annual conference, Mr Varadkar said the process of drawing up laws to enact the recommendations will begin in the New Year with most of the legislation expected to be in place by the end of next year.

The Tánaiste said he does not see constitutional issues with the proposals but that he thinks they will end up in the courts.

He added however that they should be strengthened by the fact that they fall under the umbrella of EU law.