Ponsonby was elected Member of Parliament for Poole in 1826 and held the seat until 1831, when he lost it in a by-election to Lord Ashley.
pˈɑːnsɑːnbi wʌz ᵻlˈɛktᵻd mˈɛmbɚɹ ʌv pˈɑːɹləmənt fɔːɹ pˈuːl ɪn wˈʌn θˈaʊzənd ˈeɪthˈʌndɹɪd twˈɛnti sˈɪks ænd hˈɛld ðə sˈiːt ʌntˈɪl wˈʌn θˈaʊzənd ˈeɪthˈʌndɹɪd θˈɜːɾi wˈʌn, wˌɛn hiː lˈɔst ɪɾ ɪn ɐ baɪᵻlˈɛkʃən tə lˈɔːɹd ˈæʃli.