Khan began his political career as Chairman of the Union Council, Phool Nagar from 1979 to 1983. He remained Vice Chairman of District Council, Kasur from 1983 to 1987 and as Chairman District Council Kasur from 1987 to 1993. He was re-elected to the Provincial Assembly of the Punjab as a candidate of Pakistan Muslim League from Constituency PP-149 in 1993 Pakistani general election. He received 31,457 votes and defeated Malik Mehr Din, a candidate of Pakistan Muslim League . He was re-elected to the Provincial Assembly of the Punjab as a candidate of PML-N from Constituency PP-149 in 1997 Pakistani general election. He received 35,049 votes and defeated a candidate of PML-J. During his tenure as Member of Punjab Assembly, he served as Provincial Minister of Punjab for Livestock and Dairy Development. He also remained Provincial Minister of Punjab for Forest, Wildlife, Fisheries and Tourism between 1997 and 1999. He ran for the seat of the Provincial Assembly of the Punjab as an independent candidate from Constituency PP-184 in 2002 Pakistani general election but was unsuccessful. He received 20488 votes and lost the seat to Rana Sarfraz Ahmed Khan, a candidate of Pakistan Muslim League . He was re-elected to the Provincial Assembly of the Punjab as a candidate of PML-N from Constituency PP-184 in 2008 Pakistani general election. He received 27,689 votes and defeated Rana Sarfraz Ahmed Khan, a candidate of PML-Q. In April 2008, he was elected as the Speaker of the Provincial Assembly of the Punjab where he continued to serve until 2013. In October 2008, he became acting Governor of Punjab. In 2011, he became acting Governor of Punjab following the assassination of Salman Taseer. He was re-elected to the Provincial Assembly of the Punjab as a candidate of PML-N from Constituency PP-184 in 2013 Pakistani general election. In June 2013, he was re-elected as the Speaker of the Provincial Assembly of the Punjab after securing 297 votes. In 2015, Khan was appointed as acting Governor of Punjab following the resignation of Mohammad Sarwar. In November 2017, he became the first speaker of the Punjab Assembly to serve two complete the assemblies full term from 2008 to 2018 and also became the longest-serving speaker of the Punjab Assembly for having in the office for more than nine years, consecutively. He was re-elected to Provincial Assembly of the Punjab as a candidate of PML-N from Constituency PP-181 in 2018 Pakistani general election. On 16 August 2018, he was replaced by Chaudhry Pervaiz Elahi as speaker of the Punjab Assembly.
