Sinn Fein president Mary Lou McDonald and vice president Michelle O’Neill are applauded by party members after McDonald’s keynote speech during the Sinn Fein ard fheis at Waterfront Hall

The DUP has accused Sinn Fein president Mary Lou McDonald of living in a "fantasy world" after her keynote address to the party's ard fheis.

Ms McDonald had claimed the Government was producing fantasy "non-solutions" to the border question over Brexit.

In a hard-hitting dismissal of her speech, DUP MP Sammy Wilson said: "When it comes to fantasies, dreams and self-delusion, Sinn Fein are sailing along on the highest clouds.

"They think they can keep Northern Ireland in the EU while the rest of the UK leaves.

"They promise to deliver on separating Northern Ireland from the UK with a border down the Irish Sea.

"Having missed the 2016 deadline of a united Ireland promised to the IRA hard men by Gerry Adams, they now promise they will use Brexit to deliver it."

Sinn Fein hoped it could get the Assembly up and running with the condition that the DUP agree to an Irish Language Act that republicans believed could "decolonise and Gaelicise Northern Ireland", Mr Wilson said.

"They haven't a chance, they can dream but we will be their worst nightmare," the DUP MP added.

"We will use our position at Westminster to ensure the Government keeps its promise to treat Northern Ireland the same as the UK. We will resist any attempts by Sinn Fein to get Stormont running again on their terms and we will argue a strong case for the Union to ensure that support for a united Ireland stays at the paltry 21% in recent polls. Dream on Mary Lou."

In her address to delegates at the ard fheis in the Waterfront Hall on Saturday, Ms McDonald said a power-sharing Executive and Assembly in Northern Ireland was the "right thing to do".

She said: "We are up for that. Michelle O'Neill stands ready to lead our team into government."

But she added: "We need partners who will legislate for the common good, not on the basis of personal prejudice or religious fundamentalism.

"Partners who place respect, reconciliation and the rights of citizens, above all else.

"Partners with a real commitment to power-sharing - to sharing power, to mutual recognition, to rights. These are things the DUP must embrace."

The Sinn Fein president claimed the DUP remained in a "fixed negative space", focused on "facilitating the Tory Brexit".

She challenged London and Dublin to "deliver on marriage equality, address the legacy of the past and deliver the Acht na Gaeilge". She said: "People in the north cannot wait while the DUP play political games and go into hiding at Westminster.

"The two governments must act to convene the inter-governmental conference without further delay. Unionism cannot and will not hold back the tide of challenge and equality."

Ms McDonald also stretched out the hand of friendship to unionists. "A new Ireland must be home for unionists. We need to understand that. We need to find ways to talk about the future," she said.

"We need to find ways of reconciling the past. These aren't easy things to do. People suffered, were hurt, endured pain, inflicted pain.

"We can't make that go away but we can say sorry to each other. I believe it is important that we do. As the leader of Sinn Fein, I pledge that we will never forget. We will work tirelessly to ensure we never return to the dark days of conflict."

The Sinn Fein president said the "new Ireland" wasn't "some far-off aspiration, some unattainable dream, its foundations must be laid in the here and now".

Unionists and republicans faced the challenge of working in common to protect Irish interests on Brexit, she said.

"Treading water, fingers crossed and hoping for the best is not a strategy at this time.

"Propping up a Tory Government that glories in wilful ignorance and indifference to Ireland is not the way forward.

"Allowing the Tories to dodge, equivocate and engage in fantasy non-solutions to the Irish question is most certainly not the answer." If Brexit's architects still couldn't agree what it looked like, that was their problem, Ms McDonald said.

"It will not become Ireland's problem. The Tories need to know that. The DUP needs to know that. The upcoming European summit is crunch time," she said.

"If the British Government can't demonstrate how they will avoid a hard border, protect the Good Friday Agreement and citizens' rights, then the Irish Government must call them out.

"There can be no question of progressing to the next phase of these negotiations in the absence of an answer to the Irish question. This is one test our government cannot fail."

Ms McDonald insisted her party's core objective remained Irish unity.

"The mechanism for achieving this is set out in the Good Friday Agreement, an Agreement that is now 20 years old," she said.

"The work to achieve it must be driven by those of us - in Sinn Fein and beyond - who passionately believe that all of our lives can be so much better in a new Ireland."

Belfast Telegraph