On 9 December 1973, after talks in Sunningdale, Berkshire, the UUP, SDLP and Alliance Party of Northern Ireland and both governments reached the Sunningdale Agreement on a cross-community government for Northern Ireland, which took office on 1 January 1974. The Provisional IRA was unimpressed, increasing the tempo of its campaign, while many unionists were outraged at the participation of Irish nationalists in the government of Northern Ireland and at the cross-border Council of Ireland. Although the pro-Sunningdale parties had a clear majority in the new Northern Ireland Assembly, the failure of the pro-Agreement parties to co-ordinate their efforts in the general election of 28 February, combined with an IRA-sponsored boycott by hardline republicans, allowed anti-Sunningdale unionists to take 51.1% of the vote and 11 of Northern Ireland's 12 seats in the UK House of Commons.