The Deputy Prime Minister has expanded and extended a public consultation over the proposals, which critics fear will rubber-stamp a controversial definition.
The consultation will now run for an extra week and a link for responses to the plans has been made public.
The move followed complaints by the Free Speech Union (FSU), which said the new definition was being drawn up behind closed doors.
The FSU wrote to Ms Rayner expressing concern that the process would enshrine a definition which treats Islamophobia as a type of racism.
The definition has been criticised for being so expansive that it could threaten free speech, act as a de facto blasphemy law and stifle legitimate criticism of Islam as a religion.
In his letter, Lord Young, the General Secretary of the FSU, said the consultation questions appeared to be “heavily weighted” in favour of a “predetermined outcome”, endorsing a definition “closely aligned” with that put forward by the all party parliamentary group (APPG) on British Muslims.
The APPG definition was adopted by Labour and stated that “Islamophobia is rooted in racism and is a type of racism that targets expressions of Muslimness or perceived Muslimness”.
Lord Young said key groups that might challenge the definition over its impact on free speech and provide alternative views had not been invited to submit evidence.
He listed Christian Concern, the Christian Institute, the Adam Smith Institute and the Equality and Human Rights Commission. Ms Rayner’s department has extended the deadline to July 20th and widened the consultees. Lord Young said it needed to give sufficient time to take on board all the responses to the plan
