Chris Heaton-Harris has been accused of “failing the people of Northern Ireland” on the eve of what is expected to be the largest strike in the region in recent history.

An estimated 150,000 public sector workers from areas including health, education, police staff, transport, roads maintenance and civil servants will take part in the walkouts over a pay award.

There have been warnings of serious disruption due to services such as road gritting being withdrawn.

Schools will be closed and hospitals operating reduced services, while the Department for Infrastructure has advised against any unnecessary travel.

There are expected to be picket lines, parades and rallies across Northern Ireland, including at Belfast City Hall, the Guildhall Square in Londonderry, Omagh court house and Enniskillen town hall.

The Secretary of State had been urged to intervene and secure the funding for the pay awards in the absence of a functioning Stormont Assembly and executive, but he insisted that public sector pay is a devolved matter.

In December Mr Heaton-Harris offered the Stormont parties a £3.3 billion package to stabilise finances in Northern Ireland, which included £600 million to settle public sector pay claims.

It will be available when the institutions are restored.

A last-ditch attempt to revive Stormont with an Assembly recall on Wednesday was not successful, with the DUP maintaining its position to not participate in devolved government until unionist concerns over post-Brexit trading arrangements are addressed.

Irish Congress of Trade Unions (Ictu) assistant general secretary Gerry Murphy said Mr Heaton-Harris’ strategy has failed.

“Today in the house of Commons, Chris Heaton-Harris repeated the same discredited line he has held throughout this crisis, that fair pay for public servants is not his responsibility, but that of a restored NI Executive,” he said.

“The secretary of state’s strategy has clearly failed and it has failed the people of Northern Ireland.

“The trade union movement have won the popular argument, as witnessed the support we have seen from women’s groups, the voluntary sector, students’ unions, the 50 chief executives in the public sector, the PSNI Chief Constable and the head of the NICS and the public at large.”

He said the strikes and rallies on Thursday will be “demonstrations of industrial and public solidarity on a scale never seen before in this place”.

“Each industrial dispute has been mandated by the votes of trade union members,” he said.

“Every stage of this campaign for fair pay and better budgets from accountable local political institutions, has had the input of small and large trade unions.

“We have worked with every political party to ensure that our message is clearly understood and our economic analysis is appreciated by all sides.

“It only remains for Chris Heaton-Harris to do the decent thing and release the funds.”

Temporary Assistant Chief Constable Melanie Jones said a significant policing operation will be in place across the day, with a visible presence at parades and picket lines.

“We are there to monitor crowds, minimise disruption and to keep everyone safe,” she said.

“A number of large parades are planned across the country including in Belfast, Derry/Londonderry, Fermanagh and Omagh.

“We anticipate some traffic disruption in these areas and have issued guidance on our social media channels about the potential for delays.

“I would encourage the public to check this guidance before they travel.

“With the icy conditions and the disruption to gritting operations, I also want to highlight the advice recently issued by the Department of Infrastructure that people should avoid unnecessary travel.

“If you do need to use the roads, please take extra care and allow additional time for your journey.”

She added: “I want to reassure the public that we have clear plans, command structures and highly capable officers in place across the country who have significant experience carrying out this type of public safety operation.”

Kerry Fleck, vice president of the Belfast and District Trades Union Council, said 150,000 workers from 16 trade unions will take part in the strike action.

“The significance of this moment should not be underestimated,” she said.

“Across Northern Ireland tomorrow we will see workers, as in many key moments in our history, set aside differences and stand together to say ‘no more’ to the push back on rights, wages and terms and conditions; ‘no more’ to the planned destruction of our public services; ‘no more’ to food banks, hungry children and freezing homes.

“Tomorrow it will again become clear that not a wheel turns or a light switches on without the intervention of a worker.

“This is a crucial moment for a renewed trade union movement to demonstrate the power that lies in the hands of all working people and that unity and solidarity are how we win a better world and defend our collective interests.”

A Northern Ireland Office spokesperson said: “Public sector pay in Northern Ireland is a devolved matter and it is for the relevant NI departments to negotiate pay policies. The UK Government has no authority to negotiate pay in Northern Ireland.

“The Secretary of State has expressed his disappointment that a new executive was not up and running to take the offer on the table and deliver it for the people of Northern Ireland before Christmas.

“The fair and generous package offered by the UK Government is worth over £3bn, including money to address public sector pay, and more than £1bn to stabilise Northern Ireland’s public services.

“However, this package is on the table and will remain there, available on day one of an incoming Northern Ireland Executive to take up.

“It is now for the NI parties to come together, restore the Executive and begin to address the challenges facing the people of Northern Ireland, including public sector pay.”