ɪn dʒˈuːn wˈʌn θˈaʊzənd ˈeɪthˈʌndɹɪd twˈɛnti sˈɛvən lˈɑːx ˈɛntɚd pˈɑːɹləmənt æz mˈɛmbɚ fɔːɹ sənt dʒˈɜːmənz ɪn kˈɔːɹnwɔːl fɚðə wˈɪɡz, ænd hˌævɪŋ hˈɛld ðæt sˈiːt ʌntˈɪl wˈʌn θˈaʊzənd ˈeɪthˈʌndɹɪd θˈɜːɾi, hiː wʌz ðˈɛn ɹᵻtˈɜːnd wɪðˌaʊt ˌɑːpəzˈɪʃən fɚðə wˈɪk bˈɜːɡz, ænd wʌz ɹˈɛɡjʊlɚli ɹˌiːᵻlˈɛktᵻd ʌntˈɪl wˈʌn θˈaʊzənd ˈeɪthˈʌndɹɪd fˈɪfti tˈuː, wˌɛn hiː wʌz dᵻfˈiːɾᵻd, baɪ wˈʌnhˈʌndɹɪd nˈaɪntiːn vˈoʊts tʊ ˈeɪɾi, baɪ sˈæmjuːl lˈeɪŋ.
In June 1827 Loch entered parliament as member for St Germans in Cornwall for the Whigs, and having held that seat until 1830, he was then returned without opposition for the Wick Burghs, and was regularly re-elected until 1852, when he was defeated, by 119 votes to 80, by Samuel Laing.