A political agreement on a range of disputes that had undermined power-sharing in Northern Ireland has left the region facing a brighter and more prosperous future, the Prime Minister has said.

David Cameron hailed the deal that emerged from marathon negotiations in Belfast involving the Executive's five parties and the UK and Irish governments.

The 'Stormont House Agreement', forged after 11 weeks' of discussions, has resolved destabilising wrangles over the administration's budget and its non-implementation of welfare reforms while establishing new structures to deal with the legacy of unsolved Troubles killings.

It achieved less progress on other vexed disputes over the flying of flags and parading, but did set out new processes to examine how to find solutions to those matters in the future.

Much of the plan has been facilitated with a £2 billion financial package from the UK government - an offer that combines some new money from the Treasury with enhanced borrowing access and flexibility.

While the blueprint awaits the formal sign off from some of the parties' governing structures, significantly it has been endorsed by the key figures in the lead parties in the administration, the Democratic Unionists and Sinn Fein.

"I am delighted that a workable agreement has been reached that can allow Northern Ireland to enjoy a brighter, more prosperous future, while at the same time finally being able to deal with its past," said Mr Cameron.

"This agreement means the UK Government has been able to offer a significant financial package that opens the way for more prosperity, stability and economic security for Northern Ireland."

First Minister and DUP leader Peter Robinson acknowledged that further work would be required on a number of the issues.

"Of course every one of us would have liked to have had a more comprehensive and complete agreement but this is as much and more than we have ever been able to do on these issues in the past," he said.

"So it is a very significant agreement."

Sinn Fein Deputy First Minister Martin McGuinness said the deal had the potential to give the Executive a "fresh start".

"And it is a fresh start we need to seize with both hands," he said.

Flanked by party leader Gerry Adams, Mr McGuinness hailed the fact that agreement had been reached on long standing issues of division between the region's politicians.

"I think it's been a remarkable achievement," he said

Significantly, the deal has found a resolution to the thorny and long running impasse over welfare reform implementation in the region. Essentially, it overcomes nationalist concerns by enabling the Executive to establish and finance its own top-up fund to support those who will lose benefits when the policies are introduced.

The dispute, and accompanying multi-million pound Treasury penalties for non-implementation, had threatened the future of the institutions.

While the Executive is still facing a hefty penalty to cover the period when reforms have not been in operation, the sum is much reduced on the £200 million plus bill it was facing.

On wider budgetary problems facing the Executive, the deal will enable ministers to balance the budget in the coming financial year.

Around £700 million of the loan facility will be used to fund a major public sector restructuring reform programme, which includes a voluntary redundancy scheme.

This proposal is part of efforts to rebalance an economy traditionally over-reliant on the state.

On the other side of the equation, the Executive has also been granted the power to set its own rates of corporation tax in an effort to stimulate private sector growth.

This will enable it to better compete for foreign direct investment with the much lower rate of business tax in operation in the Republic of Ireland.

The document also sets out steps to trim the size of the powersharing institutions, by reducing both the number of Executive departments and Assembly members.

In regard to the past, new mechanisms, supported by £150 million of the Government's package, will be established to take on investigations into historic Troubles killings. These will take on the responsibilities of the police and the police ombudsman. Legacy inquests will remain under the remit of the coroners' courts.

Less progress has been achieved in regard to disputes over parades and the flying of flags but the agreement does set out future ways of potentially finding resolutions to both issues.