Sinn Féin in publishing a new discussion document on a united Ireland in Belfast and Dublin on Monday has described as a "myth" the argument that the Republic could not afford unity.
Sinn Féin in launching the document, Towards a United Ireland at Stormont said the only way to uphold the wishes of the people of Northern Ireland who voted by 56 per cent to remain in the European Union was through a united Ireland.
The document contends that “Brexit changes everything”.
The Sinn Féin president Gerry Adams, in a foreword to the document, said: "The Brexit referendum result has swept away many of the previous political assumptions about the constitutional, political and economic status quo in Ireland. Ireland's political landscape, North and South, has been transformed dramatically."
Sinn Féin called for a joint referendums North and South on a united Ireland to be carried out in the next political term and issued assurances that the British cultural identity of unionists would be respected if the country was unified.
The document also addressed the arguments that the Republic could not afford to see a united Ireland. According to British government official figures the North over recent years has an annual budget of about £24 billion but suffers an annual deficit, again over recent years, of between £9 and £11 billion.
This £10 billion shortfall is met through annual subvention by the British government.
Sinn Féin however in its document disputed this figure. In a section entitled, “the Unaffordability Myth” it said that commentators have estimated the total annual Northern Ireland budget at £24.1 billion.
Sinn Féin said “over-estimates of the North’s fiscal deficit are a political ploy aimed at closing down any debate on Irish unity”. It estimated that the actual annual deficit is between £2.7 billion and £5.1 billion”.
“Much of the debate around the financial aspects of Irish unity has focused on the question of whether Ireland can afford unity. The truth is that the British subvention to the North annually could be as low as £2.7 billion and this is in a scenario where the North’s economic potential has been severely constricted by Westminster,” it said.
"While there is a legitimate concern as to the cost and benefits of unity, the issue of affordability has been subject to wild speculation and the British Government has refused to fully open the books."
The document said that a recent report by the British Chartered Institute of Public Finance shows that the North has greater assets (£51.8 billion) than liabilities (£51.3 billion).
The document: “In the absence of precise information from the British Treasury which can be independently verified, the variety of figures creates confusion - which is perhaps intentional. What can be said with certainty is that the £24.1billion figure is not accurate and that public spending is probably in the £18.3 billion to £20 billion range.”
Sinn Féin further called for the creation of an all-Ireland national health service which it also argued was affordable.
The document goes on to say “a new and unified Ireland will be pluralist, inclusive and accommodating to all our people in all their diversity”.
“The Orange tradition is an Irish tradition and the British identity of many people in the North must be accommodated in an agreed, united Ireland,” it added.
Sinn Féin stated that unity would require a new constitution and new symbols and emblems to reflect an inclusive, agreed Ireland.
People who held British citizenship could continue to do so and pass on this right to their children.
There would be “constitutional recognition of the unique identity of Northern unionists and the British cultural identity of a significant number of people in the North of Ireland” and “expression being given to the relationship between unionists and the British monarchy”.
There also would be “recognition of the place of the loyal institutions (including the Orange Order) in the cultural life of the nation” and “changes to the Irish Constitution to remove the overt influence of any one church or faith”.
The document said: “Currently, unionists in Ireland remain isolated on the margins of the British political system, where they make up less than 2 per cent of the population. There are also significant demographic changes occurring in the North as a result of which those who identify themselves as British are declining while those who identify as Irish or Northern Irish are increasing.
“In a united Ireland, unionists would make up 20 per cent of the population and exercise real authority, power and influence - as opposed to being a tiny minority largely ignored within the British parliamentary system. All of this creates an opportunity for a more open, imaginative and accommodating approach to reunification.”
Sinn Féin, in the document, said unity could involve continued devolution to Stormont, a federal or confederal Ireland or other unspecified arrangements.
It calls for the Government to publish a consultation document on unity, establish an Oireachtas joint committee on a united Ireland, and the appointment of a Government minister of state "with the dedicated and specific responsibility of developing strategies to advance Irish unity and coordinating the Government's all-Ireland policies".
The document is being launched in Belfast by deputy first minister Martin McGuinness and TD Louise O'Reilly, and in Dublin by TD Mary Lou McDonald, MEP Matt Carthy and Assembly member Máirtín Ó Muilleoir.