He subsequently established the United Kingdom Unionist Party to contest elections to the Northern Ireland Forum and the related talks which started in 1996.
He was committed to a policy of integration for Northern Ireland, whereby legislative devolution would no longer be Westminster's abiding policy, there would be no Stormont Legislative Assembly and the province would be a fully participating part of the United Kingdom; at the same time, the three main British political parties would fully organise in Northern Ireland.
[3] These integrationist policies, once popular in some sections of Unionism, receded with the introduction of devolution to Scotland and Wales, and the creation of a functioning Northern Ireland Assembly.
However it is the case that other parts of the United Kingdom with devolved assemblies are fully covered by the three main British political parties, but not Northern Ireland.
In October 2009, McCartney was guest speaker at the Traditional Unionist Voice party conference in Belfast, where he spoke on the situation surrounding the primary school transfer test, brought about by a Sinn Féin Education Minister.