The Government is to appeal a recent High Court ruling that legislation underpinning legally enforceable sectoral wage agreements is unconstitutional.

The ruling by Mr Justice Garrett Simons created uncertainty for thousands of workers in engineering, whose pay and conditions were governed by Sectoral Employment Orders (SEOs).

The ruling means many particularly lower paid employees will only have a legal entitlement to the National Minimum Wage and other basic statutory protections, rather than to better sectoral minimum rates and conditions established through negotiation between employers and unions and the setting of legally binding Sectoral Employment Orders.

These conditions were negotiated between employers and unions under the oversight of the Labour Court.

Responding to a query from Labour leader Alan Kelly, Minister for Enterprise Trade and Employment Leo Varadkar confirmed that it was the Government's intention to appeal the judgment to the Supreme Court.

Mr Varadkar said he came to that decision after consulting with Minister of State Damien English and seeking the advice of the Attorney General.

He said the Government had until 14 July, next Tuesday, to lodge that appeal.

However, he stressed that he wanted to send out a clear message to go out to all workers affected and their employers.

He said that until the case is heard in the Supreme Court, and until the court makes its judgment, "there can be no diminution in their terms and conditions unilaterally by any employer."

A number of unions are already planning what they call "protective" ballots for industrial action in case any employers seek to reduce the terms and conditions covered by SEOs.

The Department of Enterprise, Trade and Employment confirmed that an application for an appeal will be lodged with both the Court of Appeal as well as the Supreme Court.

If the Supreme Court grants a "leapfrog", then the appeal to the Court of Appeal will be abandoned.

The appeals will be lodged within 28 days after the judge has issued an order giving effect to his High Court ruling.