Complex sentence: He immediately formed the New Party, with policies based on his memorandum, but despite winning 16% of the vote at a by-election in Ashton-under-Lyne in early 1931, the party failed to achieve any other electoral success.
Split into simpler sentences: He immediately formed the New Party, with policies based on his memorandum. Despite winning 16% of the vote at a by-election in Ashton-under-Lyne in early 1931, however, the party failed to achieve any other electoral success.