In 1921 he became the member of
Punjab Legislative Council and then became its vice president but he resigned from both vice presidency and membership of the council on 11 November 1921, as a protest against British Government for taking away the keys of
Harimandir Sahib treasury and he plunged into the Gurdwara Reform Movement. On 26 November 1921, was arrested at
Ajnala in an Akali Diwan on the charge of making a seditious speech and sentenced to 6 months imprisonment, with a fine of Rs. 1000. In the absence of
Baba Kharak Singh in jail, Mehtab Singh acted as President of Shiromani Gurdwara Prabandhak Committee. He was again arrested in the
Gurdwara Guru ka Bagh agitation in 1922. In October 1923 when SGPC and SAD were declared unlawful organisations, he again with other leaders detained. He was one of the Seven delegates of All Parties Conference at Delhi on 24 February 1928. At All Parties Convention at
Calcutta on 28 and 29 December 1928, he strongly opposed the views of
Mohammed Ali Jinnah. He was the president of the committee for the notified
Sikh Gurdwaras at
Nankana Sahib from 1933 to 1936. Mehtab Singh died of Heart attack on 23 May 1938. ==References==