[19] She was also the local party's spokeswoman for children and young people[20] and sat on the council's Joint Consultative Committee for teachers.

[13] For the 2017 general election, Onasanya was selected by the Labour Party to stand in the constituency of Peterborough, which had been held since 2005 by Stewart Jackson, a Conservative.

[23][24] She attracted some notice when she quoted lyrics from Man's Not Hot, a viral song, during a budget debate in November 2017.

[27] After being found guilty of perverting the course of justice, it was announced in January 2019 that she had been expelled from the Labour Party in December 2018.

[28] On 4 April, Onasanya voted to legally require the Prime Minister to seek an extension of Article 50 from the European Union.

[31] In late April, Onasanya made her only speech in the Commons during the period between her release from prison and losing her seat as a result of the successful recall petition.

[36] On 13 August 2018 at the Old Bailey, she pleaded not guilty to the one charge against her, relating to an alleged offence in Thorney, Cambridgeshire, in July 2017.

[38] A week before he was due to face trial with his sister, Festus Onasanya admitted three counts of perverting the course of justice.

[45] Onasanya continued to protest her innocence, saying in a message to other Labour MPs that she was "in good biblical company along with Joseph, Moses, Daniel and his three Hebrew friends who were each found guilty by the courts of their day", and that "Christ ... was accused and convicted by the courts of his day and yet this was not his end but rather the beginning of the next chapter in his story".

[50] As she received a custodial sentence, but of less than 12 months, a recall petition would be started after the appeal process had concluded.

[8][49] (A custodial sentence of more than a year, including a suspended one, would have led to her being removed as an MP automatically, in accordance with the Representation of the People Act 1981.

[64][65] In August 2019 a disciplinary tribunal of the Solicitors Regulation Authority struck Onasanya from the roll of solicitors and ordered her to pay costs of £6,562, after finding that she had "failed to act with integrity", had not "(upheld) the rule of law and proper administration of justice" and had "acted dishonestly".

[67][68] It has been claimed that her religious beliefs partly stem from being involved in a road traffic collision as a child, when, although Onasanya was badly injured, her mother took her home and prayed rather than taking her to hospital.

[69] She is a patron of Women Worldwide Advocating Freedom and Equality[70] and was a trustee of East Hertfordshire YMCA, which closed in June 2018.

[72] In June 2020, Onasanya attracted national and international attention by accusing Kellogg's of racism for using a monkey as the mascot of their Coco Pops cereal.