Complex sentence: He lost his seat in the 1900 Canadian election but returned to parliament in 1904, this time representing a Toronto area riding, and remained an Opposition MP until his party returned to government in the 1911 federal election under Robert Borden.
Split into simpler sentences: He lost his seat in the 1900 election but returned to parliament in 1904, this time representing a Toronto area riding. He remained an Opposition Member of Parliament (MP) until his party returned to government in the 1911 federal election under Robert Borden.