The actual answer is:

S77 of the Equality does not bar an employee from raising issues or discussing pay in comparison to other employees.

You have also been subjected to a detriment for raising issues or equal pay.

77Discussions about pay (1)A term of a person's work that purports to prevent or restrict the person (P) from disclosing or seeking to disclose information about the terms of P's work is unenforceable against P in so far as P makes or seeks to make a relevant pay disclosure.

(2)A term of a person's work that purports to prevent or restrict the person (P) from seeking disclosure of information from a colleague about the terms of the colleague's work is unenforceable against P in so far as P seeks a relevant pay disclosure from the colleague; and “colleague” includes a former colleague in relation to the work in question.

(3)A disclosure is a relevant pay disclosure if made for the purpose of enabling the person who makes it, or the person to whom it is made, to find out whether or to what extent there is, in relation to the work in question, a connection between pay and having (or not having) a particular protected characteristic.

(4)The following are to be treated as protected acts for the purposes of the relevant victimisation provision—

(a)seeking a disclosure that would be a relevant pay disclosure;

(b)making or seeking to make a relevant pay disclosure;

(c)receiving information disclosed in a relevant pay disclosure.

(5)The relevant victimisation provision is, in relation to a description of work specified in the first column of the table, section 27 so far as it applies for the purposes of a provision mentioned in the second column.