The survey conducted from February 2-3 also showed that even a majority (61%) of those who voted for the ruling Conservative Party in the 2019 general elections shared that opinion.
Asked about the impact of the so-called "partygate" on UK politics, 88% said it was damaging to Johnson, while 84% thought it would harm the Conservative Party.
The UK prime minister has been grappling with calls to resign after a series of revelations showed that several social gatherings were held at his offices throughout 2020 and 2021, flouting COVID-19 social distancing rules.
An internal probe into the parties found that there were serious "failures of leadership and judgment" in Downing Street and that the events "should not have been allowed to take place."
The London Metropolitan Police have launched their own probe into the social events held at the prime minister’s residence.