Mr Adams told party delegates at their Ard Fheis that unionist and republican ministers have worked together at Stormont to combat cuts imposed from London.

He spoke of the advantages a single island economy could bring - and said harmonising systems north and south of the border would save money and create jobs.

"Sinn Féin wants to demonstrate to unionists that a united Ireland is also in their interests," he told the conference in Killarney, Co Kerry.

"A United Ireland makes sense. A single island economy makes sense.

"It does not make sense on an island this size and with a population of six million, to have two states, two bureaucracies, two sets of government departments, and two sets of agencies competing for inward investment.

"Harmonising our systems will save money, improve efficiency and create jobs.

"A new, agreed united Ireland will emerge through a genuine process of national reconciliation."

He also repeated a political attack on Secretary of State Owen Paterson, criticising his record in office and recommending he "do us all a favour and go back to England where he belongs".

Mr Adams continued: "The political institutions in the North need to move to the next stage - the transfer of fiscal power to the Assembly and Executive.

"The continuing exercise of fiscal power by the British Treasury will lead to more cuts in the block grant and more right wing welfare policies being imposed on us."

Meanwhile in his speech, deputy First Minister Martin McGuinness offered dissident republicans an opportunity to meet for talks.

He described the armed groups as the "enemies of Ireland" and said they are engaged in "pointless" violence.

However he said they can still play a role in the "process of building a new Republic".

The comments came after it was revealed that Sinn Féin is in talks with members of the Protestant community and churches in NI to discuss the subject of reconciliation.