Career
He was a senator from 1977 to 2002, and was noted in the Seanad for his interest in foreign affairs, particularly humanitarian issues and the Palestinian cause. In the subsequent elections to the 14th Seanad, he was elected on the Industrial and Commercial Panel. Lanigan stood again for the Dáil at the 1981 general election and November 1982 general elections in Carlow–Kilkenny, but was unsuccessful on both occasions.
He was re-elected by the Industrial and Commercial Panel to each successive Seanad until his defeat at the 1989 elections, when he was nominated by the Taoiseach, Charles Haughey, to the 19th Seanad.
The Industrial and Commercial Panel re-elected him in 1992 to the 20th and in 1997 to the 21st Seanad, but he did not contest the 2002 elections to the 22nd Seanad. Lanigan was leader of the opposition Fianna Fáil group in the 17th Seanad (1983–1987), and was Leader of the Seanad in the 18th Seanad (1987–1989).
He was reappointed as Leader in the 19th Seanad (1989–1993), but resigned (along with all the Fianna Fáil whips) in May 1990 after the government lost a series of votes when no Fianna Fáil senators were present in the chamber. He later served as Chairman of the Oireachtas Joint Committee on Foreign Affairs.
Lanigan was noted as a supporter of independent Palestinian state.
In December 2003 he was awarded the Order of Bethlehem by Palestinian President Yasser Arafat. The Order, which is the highest honour bestowed on behalf of the Palestinian people, was made at a ceremony in Ramallah in which Arafat commended Lanigan for having supported the Palestinian cause "when it was not popular to do so". Lanigan continues to be involved with the Palestinian cause, in his capacity as chairman of Irish Medical Aid for Palestine.