Most Dominant Party:Democrats(1932-1980),Liberals(1935-1984),Tories(1931-1997)

[Blair]

Worth noting the Tories went through 1940-1951 without actually being in any dominance- likewise the party really was a bystander throughout 1963-1979 (the 4 years of Heath were a sh**tshow)

[Blair]

As I said earlier the Tories interwar dominance was a rather strange hybrid- they were a national government from 1931-1935, and then again from 1940-1945. These were not years of Tory dominance.  

As Al said- you can't just use years, or the length of term as a yardstick for dominance- especially when Labour's six years between 1945-1951 did more to reshape the political structure than nearly any other 20th century government.

I also don't know how anyone can claim that the years of 1963-1979, which were dominated by social liberation, culture backlash (powellism) and industrial unrest were at all a period of Tory dominance.