A dossier of more than 300 allegations of Islamophobia in the Conservative party has been submitted to the Equalities and Human Rights Commission, increasing pressure on the watchdog to launch a formal investigation.

The submission from the Muslim Council of Britain (MCB) catalogues evidence of allegedly Islamophobic comments and actions by hundreds of activists, councillors, and advisers to the prime minister.

It also includes comments made by Tory candidates in the election who later became MPs, two of which were first revealed by the Guardian.

Sally-Ann Hart, the MP for Hastings and Rye, was put under investigation by the party for sharing a post claiming a women’s march had been hijacked by the Muslim Brotherhood to promote the “Muslim agenda”. Anthony Browne, the MP for South Cambridgeshire, questioned the loyalty of Muslims to Britain when responding to Muslim leaders’ concerns about the Iraq war. Karl McCartney, the MP for Lincoln, retweeted Islamophobic and antisemitic posts by Tommy Robinson and Katie Hopkins. Browne and McCartney apologised for their actions.

The MCB also highlighted the role of Dominic Cummings, the prime minister’s de facto chief of staff, in having responsibility for the Spectator website when a controversial cartoon of the prophet Muhammad with a bomb in his turban was posted, with a caption feeding into a far-right, Islamophobic trope about a Muslim “takeover”.

Another example was that of Andrew Sabisky, briefly a No 10 adviser, who questioned in a book review whether a growing Muslim population would be countered with violent resistance.

The dossier also includes allegations against Boris Johnson himself, who has previously apologised for describing Muslim women wearing face-covering veils as looking like “letterboxes”.

The MCB first sent a file of 150 cases to the EHRC 10 months ago. However, the watchdog has resisted launching an inquiry until it can see the terms of reference of the Tories’ independent investigation into prejudice within the party.

With no action so far, the MCB said it was sending another 150 cases and accused the EHRC, which launched an investigation in allegations of antisemitism in the Labour party last year, of failing to act on evidence of “institutional, systemic and widespread” Islamophobia in the Conservative party.

The secretary general of the MCB, Harun Khan, which represents 500 Muslim groups, mosques and charities, said: “Having furnished the Equality and Human Rights Commission with evidence of over 100 incidents of Islamophobia in the Conservative party 10 months ago, we find it extraordinary that the commission has failed to give any response, let alone inform us and British Muslims as to whether action will be taken.

“Two years ago, we estimated that there were cases of Islamophobia being identified in the party on a weekly basis. Now, with over 300 documented incidents, it appears our estimation was too low. There is no doubt that the Conservative party has an Islamophobia crisis. The party’s response has been one of denial, dismissal and deceit.

“This results in clear discrimination against Muslims because of their religion. Islamophobia is never acceptable, yet this dossier cites hundreds of individuals – including many in significant positions of power and influence – who have made horribly offensive comments about Muslims that would not be tolerated for any other section in our society.”

He said the EHRC had a duty to uphold the Equality Act and called on the watchdog to take the wealth of evidence into account by launching a formal investigation.

On becoming prime minister, Johnson had pledged to launch an inquiry into all forms of discrimination, including Islamophobia, before the end of last year. However, the terms of reference have still not been published.

A spokesperson from the EHRC said: “We are actively considering what, if any, action we may take in relation to the handling of Islamophobia and other discrimination within the Conservative party. We are also awaiting the final terms of reference of the party’s independent review which we will consider as part of our decision-making process.”