BELFAST (Reuters) - The leaders of Northern Ireland’s Irish nationalist and British unionist communities clinched a deal to prevent its power-sharing administration from collapsing, the British and Irish governments said on Tuesday.

Britain's Northern Ireland Secretary Theresa Villiers speaks on the fourth day of the Conservative Party Conference in Manchester northern Britain, October 7, 2015. REUTERS/Suzanne Plunkett

Mainly Catholic Irish nationalists and mainly Protestant unionists are obliged to share power under a 1998 peace deal that ended decades of violence, but disagreements have paralyzed lawmaking in recent years and the administration was brought to the brink in September.

“This breakthrough today is an important turning point for Northern Ireland,” British Prime Minister David Cameron said in a statement, two months after power-sharing ground to a halt over a murder linked to members of the Irish Republican Army.

“The agreement secures sustainability for Northern Ireland’s budget, sets out how we’ll deal with paramilitary groups and could provide a basis for a shared future for the people of Northern Ireland.”

Talks on dealing with historic crimes, the use of flags in the province and the implementation of social welfare cuts have been held intermittently for over a year and in late 2014 led to the Stormont House Agreement, which quickly unraveled.

Under the 67-page, ‘A Fresh Start’ agreement, the British provinces’ finances will be topped up by an additional £500 million from London to tackle issues “unique to Northern Ireland” such as the removal of so-called “peace walls”, 15-metre-high ‘fences’ that separate some among the communities.

Northern Ireland will retain the most generous social welfare system in the United Kingdom by diverting funds from elsewhere, Britain’s Northern Ireland Minister Theresa Villiers said, while the way will be cleared for the corporation tax rate to be cut to 12.5 percent by 2018 to better compete with Ireland for foreign direct investment.

However, the parties could not agree on how to deal with the legacy of the past and how official documents are disclosed. First Minister Peter Robinson said it was unfortunate but that they would not duck the issue and seek to find a solution.

The 1998 power-sharing deal ended three decades of tit-for-tat killings between Catholic Irish nationalists, who want the province to unite with Ireland, and Protestant unionists, who want to remain part of the United Kingdom, that left 3,600 dead.

But critics say compulsory power-sharing has lead to political paralysis that is damaging the economy, the most dependent on state spending of the four constituent nations of the United Kingdom.