He worked as a tea merchant in London from 1880. He was an unsuccessful Liberal candidate for Truro at the 1886 general election and in 1888 appointed Ramsay MacDonald as a private secretary. Lough was Liberal Member of Parliament (MP) for Islington West from 1892 until 1918. He was Parliamentary Secretary to the Board of Education from 1905 until 1908.
Thomas along with his younger brother Arthur Steel Lough were pioneers of the Drummully Agricultural Co-operative & Dairy Society in 1896, later to become Killeshandra Co-operative Agricultural Dairy Society and progressed to become one of Ireland's leading dairy companies, now internationally known as Lakeland Dairies.
- Laybourn, Keith (2002). Fifty Key Figures in Twentieth-century British Politics. ISBN 9780415226769.
- Catalogue of the papers of John Redmond, Collection list 118, National Library of Ireland, p. 233. Available from: http://www.nli.ie/en/ManuscriptListResult.aspx?NameSrKey=redmond&CategorySrKey=&ListNumberSrKey=&SortAction=&SortOrderAction=asc&ResultsReqKey=
|Parliament of the United Kingdom|
| Member of Parliament for Islington West
Sir George Elliott
Sir William Anson
| Parliamentary Secretary to the Board of Education
Edward James Saunderson
| Lord Lieutenant of Cavan