Increased government focus on the problems of Northern Ireland led, in 1993, to the two prime ministers signing the Downing Street Declaration. At the same time Gerry Adams, leader of Sinn Féin, and John Hume, leader of the Social Democratic and Labour Party, engaged in talks. The UK political landscape changed dramatically when the 1997 general election saw the return of a Labour government, led by prime minister Tony Blair, with a large parliamentary majority. A new leader of the Ulster Unionist Party, David Trimble, initially perceived as a hardliner, brought his party into the all-party negotiations which in 1998 produced the Belfast Agreement ("Good Friday Agreement"), signed by eight parties on 10 April 1998, although not involving Ian Paisley's Democratic Unionist Party or the UK Unionist Party. A majority of both communities in Northern Ireland approved this Agreement, as did the people of the Republic of Ireland, both by referendum on 22 May 1998. The Republic amended its constitution, to replace a claim it made to the territory of Northern Ireland with an affirmation of the right of all the people of Ireland to be part of the Irish nation and a declaration of an aspiration towards a United Ireland (see the Nineteenth Amendment of the Constitution of Ireland).