Lewis was elected as Member of Parliament (MP) for the two-seat constituency of Bolton at the 1945 general election. The constituency was divided in a boundary review for the 1950 general election, when he was returned as MP for the new Bolton West constituency.
At the 1951 general election he lost his seat to the Liberal candidate Arthur Holt.
In July 1951, Lewis reported to the House of Commons Committee of Privileges to respond to charges he tried to use Parliamentary privilege to escape charges that he drove into a policeman on his way to Parliament. Statements from witnesses said the MP, who was late for a division hit the traffic officer three times.
The committee concluded that privilege for an MP was not “above the ordinary restraints of law which apply to fellow citizens. They do not discharge the member from obligations to society, which apply to him as much and perhaps more closely in that capacity as they apply to other subjects of The Crown.”