Late last month, protesters deposited a sizable amount of foul-smelling green water on the steps of Stormont to draw attention to the appalling state of Lough Neagh, the largest freshwater lake in the British Isles. Years of agricultural pollution have created an environmental disaster in an area of huge ecological significance that once inspired the poetry of Seamus Heaney. Its plight should be a top priority for Northern Ireland’s devolved government. But the executive currently has other matters on its mind.

The sentencing of the former leader of the Democratic Unionist party (DUP) Jeffrey Donaldson, after he was convicted of child sexual abuse, dominated Thursday’s headlines. Meanwhile, a cross-party political crisis continues to play out. Halfway through the financial year, Stormont has yet to set a budget. The current deadlock in negotiations with the Northern Ireland secretary, Sir Chris Bryant, could lead to one being imposed from Westminster. Cuts are already being made by default amid an atmosphere of stasis and policy drift.

An unwelcome revival of sectarian tension on the streets is further undermining the fragile political institutions established by the Good Friday agreement. On Monday, Northern Ireland assembly members debated a motion of no confidence in the first minister, Michelle O’Neill. The move followed the Sinn Féin vice-president’s participation in protests against a proposed Orange Order march on the Garvaghy Road in Portadown, controversially sanctioned by the Parades Commission for the first time in 28 years.

A prolonged standoff between unionists and mainly Catholic residents ended peacefully, after Sir Chris banned the parade on police advice. The absence of violence was a silver lining, but the episode showcased the dangers of what one politician described as “negative nostalgia”. As those seeking to revive a route notoriously associated with loyalist violence surely anticipated, the bitter row has reopened old wounds and unleashed latent animosities.

The motion of no confidence in Ms O’Neill was a performative exercise, with no chance of obtaining the necessary cross-community support. But the combination of no budget and a renewed culture-war confrontation means that Northern Ireland now risks being governed by a zombie administration until elections next May.

Given the dismal recent track record of Stormont collapses and suspensions, that should prompt some hard thinking in London and Dublin as well as Belfast. The scandalous condition of Lough Neagh symbolises the deficiencies of a polity that now seems trapped in an endless cycle of dysfunction. The steady deterioration of public services such as healthcare, education and policing can partly be attributed to underfunding. But matters have been made much worse by the existence of a political vacuum and sectarian grandstanding where effective government should be.

Power-sharing designed to reassure nationalist and unionist communities remains indispensable. But a loveless-marriage model that allows the largest party on either side of the divide to routinely bring assembly business to a halt is in urgent need of reform. Otherwise, faith in Stormont’s ability to act in the name of the common good is in danger of evaporating. Huge strides have been made in civil society since the Good Friday agreement was struck nearly three decades ago. But Northern Ireland’s voters currently do not have the politics they deserve.

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