Hilary trained as a social worker, and worked in the north east of England. She moved into community work, then taught on the Community and Youth Work course at Sunderland Polytechnic. She became the Member of Parliament for North West Durham in 1987, and became Minister for Local Government and Housing in 1997. Hilary was instrumental in the early programme of the Social Exclusion Unit, and in the cross departmental Sure-Start ministerial committee. She was the Minister responsible for reducing rough sleeping in England by more than two thirds in two years.
After 5 years as Government Chief Whip, Hilary returned to her commitment to tackling social exclusion when she was appointed as the first Cabinet Minister to have responsibility for Social Exclusion in 2006. She persuaded colleagues to support effective early intervention Programmes, and was instrumental in bringing the Nurse-Family Partnership to England, where a pilot covering 10 areas was established.
She resigned from government in 2007, and from Parliament in 2010. She was appointed to the House of Lords in July 2010, and has continued her interest in early intervention and was responsible for the launch of Family Nurse Partnership in the UK.