UNITE Scotland has called for the full devolution of employment law to the Scottish Parliament after new Conservative business secretary Sajid Javid said there will be "significant changes" to strike laws under the new government.

The union said the plans mark "a new generation of attacks on trade union rights".

Under the plans, a strike affecting essential public services would need the backing of 40% of eligible union members under government plans, he said. Currently, a strike is valid if backed by a majority of those balloted.

There will also need to be a minimum 50% turnout in strike ballots.

Unite Scotland said the plans which also involve lifting restrictions on the use of agency staff to break strikes would exacerbate "some of the most restrictive trade union laws in Europe while giving opportunistic employers an open goal to attack terms, conditions and collective agreements".

Unite has previously argued for the employment law agenda to be transferred to the Scottish Parliament in its contributions to the Smith Commission and it will make representations on Wednesday to the First Minister, Nicola Sturgeon, arguing that the "regressive" Tory plans are "incompatible" with the founding principles of the Fair Work Commission.

Unite Scottish Secretary Pat Rafferty said, "I will be making it clear to the First Minister that the employment law agenda should be fully devolved to the Scottish Parliament, not only to grow shared prosperity in Scotland but to spearhead the anti-austerity agenda.

"It's no surprise that the Tories have moved quickly to continue the Thatcher anti-trade union agenda at the earliest opportunity - the warning signs were there in the previous coalition - and this will be an unmitigated disaster for working families struggling to deal with the cost of living.

"It is fact that the assault on trade union and collective rights during the 1980s and early 90s proved a significant driver in the increase of UK income inequality over the last thirty years; there is a direct correlation between trade union decline and the rising gap between the rich and the poor.

"We have worked with the Scottish Government on the Fair Work Commission to advance the role and responsibilities of trade unions across Scottish employment and the First Minister has said that the Commission's work is at the heart of their strategy to promote economic growth and equality.

"If the rhetoric is to become reality then the Scottish Government will support our views and agree that these regressive plans are incompatible with fairer employment and a just society."

The changes to the law are to be announced in the Queen's Speech which will take place later this month.

Unite is Britain's biggest union with 1.42 million members in every type of workplace.

Mr Javid said: "We have already made clear in terms of strike laws that there will be some significant changes.

"We've said that there will be a minimum threshold in terms of turnout of 50% of those entitled to vote.

"We have also said that when it comes to essential public services, at least 40% of people need to vote for strike action.

"And we've said we're going to lift the ban on the use of agency staff when strike action takes place.

"That's something we'll give more detail on in the Queen's Speech but it will be a priority."

He added: "I think it's also something that needs to be done.

"We need to update our strike laws and we've never hidden away from the changes we want to make."