After his release, and another conviction in the Republic of Ireland for IRA membership, he became increasingly prominent in Sinn Féin, the political wing of the republican movement. He was in indirect contact with British intelligence during the 1981 hunger strikes, and again in the early 1990s. He was elected to the Northern Ireland Assembly at Stormont in 1982, representing Londonderry. He was the second candidate elected after Social Democratic and Labour Party (SDLP) leader John Hume. As with all elected members of Sinn Féin and the SDLP, he did not take up his seat. On 9 December 1982, McGuinness, Gerry Adams and Danny Morrison were banned from entering Great Britain under the Prevention of Terrorism Act by the Home Secretary, William Whitelaw.