He served as a European Parliament assistant to Ian Paisley from 1980 to 1982. In 1982 he was elected as a Member of the Northern Ireland Assembly at Stormont for North Antrim and served as the DUP Assembly Chief Whip. In 1983 Allister stated that if the DUP were faced with a choice between no devolved government and a power-sharing government with the SDLP or other Nationalist representatives, his party would opt for not having a devolved government. He was also the Vice-Chairman of Scrutiny Committee of Department of Finance and Personnel from October 1982 to June 1986. Outside the Stormont Assembly, he was a member of Newtownabbey Borough Council from 1985 to 1987. In 1983, he stood as a DUP candidate in the Westminster election for East Antrim. However, he narrowly lost to Roy Beggs following a bitter campaign in which he denounced Beggs as a "political gypsy" for leaving the DUP and joining the OUP; Beggs had resigned from the DUP after leading a Larne council delegation to Dún Laoghaire in the Republic of Ireland. In August 1985 Allister attended the first major meeting of the United Ulster Loyalist Front (UULF) in Portadown. The UULF had originally formed as a committee earlier that year to oppose police plans to reroute traditional Orange Order parades away from nationalist areas of Portadown. The UULF was supported by the Ulster Defence Association (UDA) with South Belfast Brigade chief and UDA deputy leader John McMichael being appointed to the coordinating committee. Unionists blamed the Irish government for loyalist parades being rerouted from predominantly Catholic areas and the UULF's stated purpose was to oppose further perceived interference from Dublin, although the group's secretary told the press ahead of the meeting that "[he] would not expect paramilitary action to be decided tonight". Following the signing of the Anglo-Irish Agreement in November 1985 by the Thatcher and FitzGerald governments, he was a high-profile opponent of the treaty. He was a member of the Joint Unionist Working Party, a body set up by his party and the Ulster Unionist Party (UUP) to oversee the unionist campaign against the Agreement. During the one-day loyalist strike against the Agreement in March 1986 it was reportedly difficult for journalists to move around the "loyalist stronghold" of Larne without the permission of Allister. He was also very vocal in his criticism of Royal Ulster Constabulary (RUC) Chief Constable John Hermon;