A message from the politician’s official Twitter account said: “Statement regarding today's vote: Jared missed the vote today because he has flu.”
It is understood this refers to a key vote in the House of Commons in which MPs have backed a bid to stop a new prime minister suspending Parliament to force through a no-deal Brexit.
Mr O’Mara has previously been criticised by constituents for failing to vote in key Brexit amendments, and his latest tweet has not gone down well with some people.
One Twitter user said it would “be easier to list which votes he has attended rather than which he missed.”
Another described it as “unacceptable” before adding: “MPs attend votes in the direst of health circumstances.”
And another tweeted: “The best way to represent your constituents would be to quit and have a by-election.”
During two turbulent years as an MP, Mr O’Mara has quit the Labour Party after being suspended over alleged historic misogynistic and homophobic comments made online.
More recently, he closed his constituency office for a month in April, there were reports that all his staff were either sacked or walked out, and he stopped holding surgeries or responding to correspondence from the public for a period of time.
However, he also told The Star just weeks ago that he has got a fresh team behind him and is operating from a new office in the city centre.
Mr O’Mara recently launched a petition calling for politicans to be able to vote remotely that would allow them to spend more time tending to matters in their constituencies.