The Government must set out a five-year spending plan for implementing Northern Ireland’s deal to restore devolution, a committee of MPs said.

A total of £2 billion of UK funding has been branded “insufficient” to meet the objectives of the agreement and the coronavirus has created another dent in the economy.

Legal changes intended to ensure Stormont cannot collapse as quickly as it did in 2017 have not yet been implemented and parliamentarians warned of the danger of “sleepwalking” into more problems.

Northern Ireland Affairs Committee chairman Simon Hoare said: “Meeting the commitments enshrined in New Decade, New Approach (NDNA) is the only way to restore trust in the devolution settlement and its ability to deliver for the people of Northern Ireland, who have been ill-served by stagnating public service provision for too long.”

New Decade, New Approach was the name given to the accord between the British Government and the five main parties in Belfast with the support of the Irish Government.

It was sealed while Julian Smith was Northern Ireland secretary after months of dialogue.

Mr Hoare said: “All parties, the Executive, UK Government and Irish Government must work constructively to meet their commitments to forge a better future for Northern Ireland and to nurture healthy devolved governance.

“The UK Government must provide a realistic and long-term financial plan that recognises the challenges imposed by coronavirus.”

His committee said the economic effects of the pandemic will exacerbate pressure on public finances in Northern Ireland.

The group of MPs took evidence about the need to prioritise commitments to enact in the agreement because insufficient funding could destabilise Stormont’s ministerial Executive.

Mr Hoare added: “No amount of money will make NDNA work without the development of a more productive working culture at Stormont.

“To restore trust, the implementation of NDNA will require regular monitoring and review.”

He said there should be no excuses for failure.

“We cannot sleepwalk into another Executive collapse, because the people of Northern Ireland deserve more.”

Powersharing was restored in January after months of negotiations between the parties.

Addressing long waiting lists for healthcare, tackling educational underachievement, boosting funding for key roads projects and renewing the sewerage system and official recognition of the Irish language  were listed as priorities in the agreement.

Stormont ministers have said not enough cash was available to meet them all.

The committee said the Government must set out a long-term financial plan for the implementation of the agreement that is costed over the next five financial years and that acknowledges the effects of Covid-19.

It said the plan should be made available before this year’s autumn budget and the Government should issue quarterly updates on its progress.

It also urged the Government to re-examine the powers to borrow funds available to the Executive and local authorities to help meet ongoing pressures and exploit the historically low cost of borrowing.

As part of the deal an Independent Fiscal Council was envisaged to assess Stormont’s finances.

The committee said its long-term success will depend on establishing strong working relationships with the Treasury and Stormont’s Department of Finance.

Stormont finance minister Conor Murphy said: “I welcome the recommendation by the Northern Ireland Affairs Committee that the British Government should put in place a long-term financial plan for the implementation of the New Decade, New Approach document.

“The funding provided by the British Government falls significantly short of what is required.

“I continue to impress upon them to deliver adequate funding to fulfil the New Decade, New Approach commitments.”