Early building watchdog vote not essential

It's likely Christmas will come before a parliamentary vote on the Turnbull government's bid to restore the Australian Building and Construction Commission.

The prime minister is hopeful of getting the numbers for legislation which helped trigger the July 2 election - but his colleagues have hinted there may not be a vote anytime soon.

"Whether it's passed this side of Christmas or the other side is not the most important thing," assistant minister Zed Seselja told reporters in Canberra on Monday.

Liberal Democrat senator David Leyonhjelm is in discussions with the government over the legislation and is looking for "offsets" in exchange for his vote.

He supports an inquiry into section 18C of the Racial Discrimination Act but it wouldn't be enough.

Asked whether he is holding the government to ransom, he replied: "How could you possibly say I'm holding the government to ransom.

"All I'm doing is, (I've) got them by the balls and I'm squeezing".