Some Brexiteers are risking fragile peace in Northern Ireland by questioning the future of the Belfast Agreement, Tánaiste Simon Coveney has said.

Mr Coveney, who is also Minister for Foreign Affairs, tweeted that the 1998 accord was being undermined in some political circles.

Mr Coveney said: “Talking down (the) Good Friday Agreement because it raises serious and genuine questions of those pursuing Brexit is not only irresponsible but reckless and potentially undermines the foundations of a fragile peace process in Northern Ireland that should never be taken for granted.”

He pointed out in a later tweet that the Belfast Agreement was “supported by referendum in Northern Ireland. The result was 71.1% in favour. A simultaneous referendum held in the Rep of Ireland produced an even larger majority (94.4%) in favour - today Irish and British Govts remain absolutely committed to GFA”.

The Irish and British governments have reiterated they are fully committed to the agreement amid a deep political impasse in Stormont and as the issue of the post-Brexit border comes to the fore.

Mr Coveney’s tweet was directed at Labour MP Kate Hoey and Conservative MPs Daniel Hannan and Owen Paterson after they raised questions over the future of the 20-year-old agreement which heralded an end to the end armed conflict in Ireland.

Mr Paterson, a former Northern Ireland secretary, recently retweeted a commentator’s suggestion that the agreement had outlived its use.

He also tweeted that Northern Ireland deserved good government, and health services were falling behind the rest of the United Kingdom without a devolved executive.

Northern Ireland Secretary Karen Bradley is due to update Westminster on the Stormont deadlock on Tuesday.

An intense round of political and diplomatic activity began in Dublin, Belfast and London on Monday in an attempt to restart talks to restore the Northern Ireland Executive. But with the Sinn Féin leader, Mary Lou McDonald, reiterating there would be no re-forming of Stormont’s powersharing Executive without an Irish language Act, and the DUP leader, Arlene Foster, calling on the British government to start “taking decisions” in the North, there appeared to be little sign of a possible breakthrough. Ms McDonald and Sinn Féin’s leader in Northern Ireland, Michelle O’Neill, met Taoiseach Leo Varadkar and Mr Coveney at Government Buildings in Dublin yesterday evening.

The Belfast Agreement was signed almost 20 years ago by the Irish and British governments and enjoyed support from most of the major parties in Northern Ireland. Ian Paisley’s DUP opposed it at the time.

It enabled the formation of a ministerial executive and assembly at Stormont.

Ms Hoey said her questions over the future of the agreement were nothing to do with Brexit.

“Hiding head in sand over viability of sustainability of mandatory coalition is reckless and wrong,” she said.

Mr Hannan said he had been arguing long before Brexit that the agreement needed to be changed.

British Prime Minister Theresa May and Taoiseach Leo Varadkar spoke by phone on Monday night after the Democratic Unionists and Sinn Féin clashed over the prospect of direct rule being imposed on Northern Ireland.

Both leaders expressed disappointment over the political impasse at Stormont.

The breakdown in powersharing came to a head despite optimism that a deal had been close on contentious issues such as the Irish language, marriage equality and the legacy of the past. - additional reporting PA