Two weeks ago, with Michelle O’Neill, the Sinn Féin leader, I led a delegation of the party to Downing Street to meet the British prime minister, Theresa May and the secretary of state, James Brokenshire. In our contribution to the discussions we warned both that doing a deal with the Democratic Unionist party in order to hold on to power carried with it huge risks, not least in the threat it could present to the Good Friday agreement.

That deal has now been reached between the DUP and Tory government. It will have long-term political consequences for the future of the Tory government at Westminster and for all of those citizens worried by the policies it intends to pursue.

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The price for this deal will be DUP support for austerity and further cuts to public services. The DUP has agreed to support the Tory government on all motions of confidence, the Queen’s speech, the budget, finance bills, money bills, supply and appropriation legislation and estimates, and all legislation pertaining to British national security and Brexit. So May now has a majority to push through her legislative programme, austerity agenda and Brexit plans.

The agreement between the DUP and the Tories will also affect the efforts in Belfast to restore the political institutions in the north. The collapse of the executive at the beginning of the year arose because the British government and the DUP refused to implement key agreements on language, equality rights and dealing with the legacy of the past – agreements that had been agreed previously.

The tipping point for the former deputy first minister Martin McGuinness was the DUP’s handling of the renewable heat incentive scandal and the allegations from within the DUP of corruption in the running of that scheme. The potential cost to the taxpayer, of £500m, was also a significant factor in Martin’s decision to resign.

In addition, over the last seven years the Tory government’s austerity policies have led to over £1bn being cut from the north of Ireland’s budget. This has had a hugely damaging impact on public services and capital infrastructure projects. The Tories refused to take account of the unique circumstances faced by people here, including the fact that we are a society coming out of conflict.

Last year the people of England and Wales voted to leave the European Union; the people of the north of Ireland and of Scotland voted to remain. The DUP and the Tories are determined to drag this part of Ireland out of the EU against the wishes of its citizens. Brexit will inflict significant economic pain on the north’s economy, as well as imposing a hard economic border on the island of Ireland. It also threatens the Good Friday agreement.

The Tory government’s commitment to scrap the Human Rights Act, end the jurisdiction of the European court of justice and end the role of the European convention on human rights is a direct attack on the human rights core of the Good Friday agreement.

All of these issues are not simply Sinn Féin issues or DUP issues. Equality, Irish language rights, human rights, marriage equality, the bill of rights are all British government issues and also Irish government issues, and those governments have to meet their obligations.

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As I write this piece, the negotiations in Belfast are incomplete. Sinn Féin’s focus in the hours and days remaining is to establish a credible, sustainable executive that deals with all the challenges facing our society.

The allocation of some additional funds to the north could help to ease the enormous pressure on our public services. This will be a good thing. Sinn Féin has been consistently lobbying both the British and Irish governments for additional funding.

However, there is an absence of detail. For example, there is no clarity on the flexibility that will be provided to the spending of remaining funding from previous allocations for shared housing and education. While there is a commitment to continue with farm support spending, there is no certainty about the British government continuing to make up any shortfall in Common Agricultural Policy (CAP) funding after Brexit.

The DUP/Tory deal commits both parties to the Good Friday agreement and its successors. This must be honoured. So there is work to be done by all of the parties and only limited time to do this.

The DUP should be minded of the words of Edward Carson speaking in 1921 on the Tory intrigues that had led him on a course that would partition Ireland: “What a fool I was. I was only a puppet, and so was Ulster, and so was Ireland, in that political game that was to get the Conservative party into power.”