Conservative peer Baroness Warsi has said she feels her campaign against Islamophobia in the party has been vindicated by an independent review which included criticism of Boris Johnson for comments about women wearing the burka.

Lady Warsi, former chairwoman of the party, had accused the Tories of “institutional racism” and submitted a dossier of 30 cases to the inquiry.

The report said it carried out “in-depth scrutiny” of the cases provided by Lady Warsi but “we concluded that her allegation of ‘institutional racism’ against the party was not borne out by evidence available to the investigation as regards the way the party handled the complaints process”.

Nonetheless, the peer said numerous findings proved the need for her six-year campaign to highlight Islamophobic sentiment in the party.

These included remarks made by Boris Johnson in newspaper columns, such as the description of burka-wearing women as looking like “letterboxes” and “bank robbers”.

Lady Warsi said the report detailed an “inadequate, inconsistent and opaque system of dealing with complaints of racism”, and welcomed the recommendation of new strategies and processes for handling them.

She tweeted: “The urgency & extent of change recommended & required by the report is an acknowledgment of the scale of the problem & evidence of a system that failed to protect victims of racism.

“It also highlights the victimisation of complainants painted as troublemakers for speaking out,” she added.

Former chancellor Sajid Javid, who made a commitment to hold an inquiry into Islamophobia a key issue in the 2019 Tory leadership contest, said the party must now accept the recommendations in the report.

“Although the investigation didn’t find any evidence of institutional or systemic anti-Muslim prejudice, it did find distressing examples of anti-Muslim sentiment at local association and individual levels, as well as serious shortcomings in the party’s complaints process,” he said.

“Stamping out discrimination, whether against Muslims or any other minority group, is an issue where our country’s political parties have a responsibility to demonstrate leadership.

“I strongly urge the Conservative Party to adopt the independent investigation’s recommendations – unconditionally and in full.”

Iman Atta, director of campaign group Tell MAMA which monitors anti-Muslim attacks, said: “All political parties in this country should have zero tolerance to anti-Muslim hatred and Islamophobia.

“Tell MAMA is well placed given the decade of work monitoring, tackling and supporting victims of anti-Muslim hatred, to assist all political parties going forward.

“There is no room for complacency whatsoever in tackling this form of poisonous hatred.”

Opposition parties seized on the report’s criticism of Mr Johnson.

Shadow women and equalities secretary Marsha de Cordova said: “This report is a damning indictment of the discrimination rife in the Conservative Party, and it goes all the way up to the Prime Minister.

“Reports of Islamophobic hate crime spiralled in the weeks after Boris Johnson likened women who wear the burka to ‘letterboxes’ and ‘bank robbers’.

“He must now issue a full and proper public apology that acknowledges the pain and hurt he has caused in the Muslim community, as well as taking meaningful action to rebuild trust, especially among Muslim women.”

SNP depute Westminster leader Kirsten Oswald said: “Boris Johnson has made a litany of overtly racist and discriminatory comments about various groups of people over the years, which have not only caused major offence but have damaged the Conservative Party and the UK’s reputation.”

The report was described as a “whitewash” by advocacy organisation Muslim Engagement and Development (Mend), which called for the Equality and Human Rights Commission to conduct an inquiry into the Tories.

Mend chief executive Azhar Qayum said: “The report fails to address the pervasive climate of Islamophobia across the party which produces complaints in the first place, instead dismissing such issues as merely giving the ‘impression’ of Islamophobia – a conclusion that is little more than gaslighting.

“Mend has thus had no choice but to insist that the EHRC launch its own investigation.”