Washington (CNN) Omarosa Manigault Newman's publisher has responded to President Donald Trump's campaign's "legal threats" over her tell-all book, saying Trump is fully able to use his "bully pulpit" to refute anything they take issue with -- but that the book will be published.

The Trump campaign also filed an arbitration action Tuesday against Manigault Newman, alleging she breached a 2016 confidentiality agreement she signed.

Responding to a letter from Charles Harder, who is litigation counsel for the Trump campaign, book publisher Simon and Schuster's outside counsel Elizabeth McNamara wrote: "While your letter generally claims that excerpts from the book contain 'disparaging statements,' it is quite telling that at no point do you claim that any specific statement in the book is false. Your client does not have a viable legal claim merely because unspecified truthful statements in the Book may embarrass the president or his associates. At base, your letter is nothing more than an obvious attempt to silence legitimate criticism of the president."

"Put simply, the book's purpose is to inform the public. Private contracts like the NDA may not be used to censor former or current government officials from speaking about non-classified information learned during the course of their public employment."

Harder did not immediately respond to a request for the letter he sent to Simon and Schuster.

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