The Ides of March may be long past but Boris Johnson has found himself, like Julius Caesar, under attack from an unusual direction – in Johnson’s case, the nation’s classical scholars.

Following his incendiary remarks about Muslim women wearing the burqa, Johnson has found his position on a charity promoting the study of classics under threat, after several members threatened to cut their ties if Johnson’s were not.

For several years, Johnson has been a high-profile supporter of Classics for All, which aims to promote the study of Greek, Latin and classical civilisation in state primary and secondary schools. During his time as mayor of London, the organisation received generous grants to finance its work.

This week, however, Johnson’s profile page as an honorary patron was removed from the organisation’s website as the board of trustees considered the criticism of Johnson’s involvement.

“The team at Classics for All is committed to increasing access to classics and works with many Muslim pupils. We do not endorse or support Boris Johnson’s statement or comments,” the organisation said in comments sent to supporters.

Following questions about Johnson’s continued involvement in the group, which includes the classics scholar Mary Beard and broadcaster Martha Kearney among its honorary patrons, Classics for All said in a statement to the Guardian: “This is currently a matter for our trustees to consider.”

We have alerted our Trustees to recent comments and the Trustees will be reviewing your concerns. https://t.co/Zsmp83O7JP — Classics For All (@classicsforall) August 14, 2018

The controversy over the former foreign secretary’s involvement was sparked by his comments regarding the burqa, in particular comparing its wearers to letter boxes and bank robbers, in a column in the Daily Telegraph last week.

A number of trustees and patrons are understood to have contacted the organisation expressing concern at Johnson’s involvement, given the charity’s efforts to promote classical studies in state schools in cities such as Birmingham, where there is a significantly higher Muslim population than the rest of the UK.

Over the past five years, Classics for All is said to have supported more than 5,000 pupils to learn Latin, in an effort to stop the long-term decline in study of classical languages.

Johnson’s role was also highlighted on social media by several leading classical scholars and academics, with some noting that Christine Hamilton had been dropped as a charity ambassador after comparing the burqa to the outfits worn by the Ku Klux Klan.

Geoffrey de Jager, the chairman of Classics for All, is understood to have written to the trustees ahead of a discussion likely to be held at a board meeting in October.

Johnson prides himself on his facility with Latin, learned during his education at Eton and Oxford University, and has long championed the study of the classics.

The Muslim Council of Britain has said Islamophobic incidents have spiked since Johnson’s article was published. Tell Mama, a group that monitors anti-Muslim incidents, said it had received an increased number of reports of abuse towards women wearing niqabs and hijabs since Johnson’s column appeared.