Liberals gave Harris the freedom to pursue a parliamentary career in Bethnal Green South West, the seat he represented on the LCC. The parliamentary seat had a chequered history; the Liberals had won the seat on eight occasions but had lost it three times. At the last election in 1918, the Liberal candidate had finished third with just 24%, behind a socialist candidate supported by the National Federation of Discharged and Demobilized Sailors and Soldiers. At the 1922 general election, Harris faced the Unionist MP who had taken the seat from the Liberals in 1914 and a Communist who had Labour Party support. The sitting Unionist member finished third and Harris re-gained the seat polling over 40% of the vote. Harris repeated his victory in 1923 when his Communist opponent ran as an official Labour Party candidate and in 1924 when that opponent once more ran as a Communist. The 1924 election was a very bad election for the Liberals nationwide but Harris's support had held up very well. During the 1924–29 parliament which was dominated by a Unionist majority, Harris worked closely with a group of radical Liberal MPs that included William Wedgwood Benn, Frank Briant, Joseph Kenworthy and Horace Crawfurd to provide opposition to the government. Harris avoided getting involved in the Liberal Party in-fighting of the time and supported the radical policy platforms of the party presented under Lloyd George's leadership. At the 1929 general election he was easily returned, thanks in part to both the Communist and Labour parties running candidates. National Government When the Liberal Party split in 1931 over the National Government, Harris supported Sir Herbert Samuel who wanted the party to stay in the National Government and fight strongly for Free Trade. At the 1931 general election, the Conservatives, who had come fourth in 1929, did not bother to run a candidate against him. Harris was re-elected with nearly 60% of the vote against an opposition split between Labour and Communist. On 14 January 1932, Harris was created a Baronet, as Sir Percy Harris of London. When the Liberal Party left the National Government following the defeat on Free Trade, Harris followed into opposition. At the 1935 general election, he faced just one opponent, a Labour Party candidate who was also opposed to the National Government. Harris held his seat with a reduced majority in a tough election for the Liberals which saw