The Muslim Council of Britain has written to Theresa May asking her if Sajid Javid was not invited to the state banquet with Donald Trump because he is of Muslim heritage.

Britain’s leading Islamic organisation asked the outgoing prime minister why the home secretary appeared to be the only senior cabinet minister not invited and whether that was done to avoid antagonising the US president.

“There are fears that our nation is willing to give up on our principles of fairness and equality for all, in order to placate President Trump, even going so far as to exclude our home secretary solely due to his Muslim heritage,” the letter concludes.

“In this letter, we are seeking to clarify whether this was actually the case,” writes Harun Khan, the secretary general of the MCB.

Javid was the most notable senior minister not to be invited to the state dinner on Monday night, where 170 guests were served with Windsor lamb and strawberry sable in the ballroom of Buckingham Palace.

As well as the prime minister, other senior cabinet ministers present included Jeremy Hunt, the foreign secretary, Phillip Hammond, the chancellor, David Lidington, the cabinet office minister, Michael Gove, the environment secretary, the defence secretary, Penny Mordaunt and the trade secretary, Liam Fox.

“We are all aware of the Islamophobia that President Trump has propagated and tolerated at the highest levels of his administration, both in rhetoric and policy,” Khan wrote, citing the Muslim travel ban, and Trump’s retweeting of posts from the far-right British group Britain First and his criticism of the London mayor, Sadiq Khan.

Javid declined to comment about the letter but he and his aides are understood to be “eminently relaxed” about the situation. The home secretary did briefly speak to the US president on Wednesday during D-day commemorations in Portsmouth.

Invitations for the event were issued by Buckingham Palace with input from Downing Street and the US embassy. Downing Street has previously only said that “the invitations to the state banquet were organised and led by Buckingham Palace”.