The New South Wales Electoral Commission has refused to back down over its recent statements about federal senator Arthur Sinodinos in a report on Liberal Party donations.

Senator Sinodinos's lawyers wrote to the commission demanding it retract references to him in the highly critical report, which found the party broke electoral laws in the lead up to the 2011 election.

Senator Sinodinos was treasurer of the party's NSW division at the time.

In a letter to the senator's legal team, chairman Keith Mason SC said the commission was not prepared to change the report.

"The commission stands by its statement and summary of facts," the letter read.

"Accordingly, the commission is not prepared to retract its decision or any part of its statement or summary of facts."

The letter reiterates the commission's key findings that senior figures in the Liberal Party had used the Free Enterprise Foundation to channel donations from anonymous donors, some of whom were banned from donating.

"Such donations were required to be disclosed whether or not from prohibited donors," Mr Mason said in the letter.

"Your client was the Honorary Treasurer at all material times."

The NSW Electoral Commission's report was published last week and announced it was withholding more than $4 million in public funding from the NSW division of the Liberal Party, unless it complied with the law and disclosed the identity of the donors.

The mention of Senator Sinodinos in the report prompted calls from the Federal Opposition for him to give a full explanation about what he knew about the Free Enterprise Foundation or resign.

In a statement issued after the Electoral Commission report was released, Senator Sinodinos complained he was not given the opportunity to comment before it was published.

"I was not given the opportunity by the commission to comment on its statement before its publication and I was not aware of the publication until shortly prior to its release," Mr Sinodinos said.

But the response from the Electoral Commission to his lawyers suggested the senator take that issue up with others in the Liberal Party.

"The party requested and received an extension of time to make submissions to the commission," Mr Mason said.

"Your client may wish to raise with [current NSW Liberal Party finance director] Simon McInnes any concerns he has about how and who Mr McInnes consulted with to prepare the party's response to commission correspondence."