After returning to The Gambia, Jatta worked for the Curriculum Development Centre from 1978 to 1983, later as senior curriculum development officer, and was also a research fellow at the International African Institute, London from 1980 to 1982. He resigned from the government in 1986 in protest of the performance of the ruling People's Progressive Party government.
Jatta founded the People's Democratic Organisation for Independence and Socialism in 1986, an opposition party to ruling president Sir Dawda Jawara and was elected its first chairperson in 1987. He is the coeditor of the party's newspaper, Foroyaa. He stood in Wulli Constituency for the PDOIS in the 1987 House of Representatives election stood and again in 1992 but finished last in both elections.
Along with Halifa Sallah, he refused the offer of a post in the Armed Forces Provisional Ruling Council government in 1994. He was briefly detained in August 1994 in defiance of the government's ban on political activities.
In 1997, Wulli Constituency was divided into two constituencies (Wulli East and Wulli West) and he won Wulli West Constituency in the 1997 national assembly election. Subsequently, he became one of the most trenchant critics in the APRC government in the country's national assembly.
He is also a member of the national assembly from Wuli West. Jatta is also the Secretary General of Wulli Adult Literacy Development Association.
