Moreing was first elected to Parliament in 1918 for Buckrose in Yorkshire, switching to Camborne in Cornwall in 1922. He was a Liberal who supported the Coalition government led by Lloyd George. At the 1923 election, following Liberal unification, he stood as the official Liberal candidate. However, he lost his seat to an Independent Liberal candidate, Leif Jones. After the election he supported Winston Churchill's efforts to revive the Conservative/Liberal coalition. He fought the 1924 election as a Constitutionalist and regained his seat from Leif Jones. After the election he took the Conservative whip. In 1929, standing as a Conservative, he lost it once again in to Jones.
Moreing's brother, Adrian Moreing, was also a mining engineer and Member of Parliament.