Labor Senator Sam Dastyari will write to the Clerk of the Senate to see what power the Senate has to appeal against the public interest immunity claim at the heart of a Tax Office decision not to identify mining companies accused of dodging tax by shifting profits offshore.

Senator Dastyari, who chairs the Senate Economics References Committee, has complained Treasurer Joe Hockey approved the decision not to reveal the companies, which are sending billions of dollars offshore as part of apparent tax-dodging strategies.

Tax Commissioner Chris Jordan said in a letter to the committee into corporate tax avoidance that Mr Hockey endorsed his decision not to release the names of 10 resources companies that transferred a combined $31.4 billion to Singapore in 2011-2012.

Mr Hockey said the decision to disclose the information of taxpayers was entirely a matter for the Commissioner of Taxation as an independent statutory office holder.

He said that confidentiality had been a key feature of Australia's taxation system since the 1950s and that "without the continued application of confidentiality provisions, we run the risk of reducing compliance with the system".