Complex sentence: He subsequently turned his attention to obtaining a seat in the UK House of Commons, and after being rejected as Conservative candidate for Holborn and St. Pancras he was selected as the party's candidate for Clwyd South in North Wales, a Labour Party safe seat.
Split into simpler sentences: He subsequently turned his attention to obtaining a seat in the UK House of Commons. After being rejected as Conservative candidate for Holborn and St. Pancras, he was selected as the party's candidate for Clwyd South in North Wales, a Labour Party safe seat.