A disgraced former Labour MP has caused outrage after she voted for the Cooper bill, which passed by a majority of one in the Commons on Wednesday.
Peterborough MP Fiona Onasanya was jailed for one month after she was convicted for lying about a speeding offence.
Despite being expelled from the Labour Party, Onasanya was not required to stand down as an MP as her sentence was less than 12 months.
In a Twitter statement, campaign group Leave.EU said: “Tonight, tag-wearing convicted criminal Fiona Onasanya helped a bill designed to frustrate the will of 17.4 million people pass through the Commons by just a single vote.
“British politics truly is a complete and utter cesspit. #DrainTheSwamp.”
Conservative Brexiteer Nadine Dorries MP said the result was “tainted” by Onasanya’s vote.
In a statement on Twitter, Onasanya said she had backed the bill because she “could not support crashing out”.