OTTAWA — The head of the sponsorship inquiry is warning he'll take the federal government to court if necessary to get access to secret government documents that could shed light on the ill-fated program.

Justice John Gomery has already been given a number of confidential cabinet papers for his investigation of the $250-million sponsorship program.

But some were edited to delete information the Liberal government claims is not relevant to the work of the inquiry.

In a letter to Alex Himelfarb, the clerk of the Privy Council and the country's top bureaucrat, Gomery says he wants to see the unedited originals so he can decide himself what's relevant.

Gomery says that, in his view, he must be the "ultimate and independent arbiter" of what information he needs and whether it should be made public.

Inquiry lawyers say discussions are continuing with the government in an effort to resolve the dispute.

But Gomery warned Himelfarb that, at some point, he may have to consider "whether or not the public interest would be better served by having the Federal Court make a decision on the issue."

The letter was dated Jan. 21 but was only made public by the inquiry Thursday -- two days after Gomery faced a challenge from former prime minister Jean Chretien.

Lawyers for Chretien have filed papers claiming the judge lacks objectivity and should step down as head of the inquiry.

That dispute could also wind up in Federal Court, further complicating the work of the inquiry.

The argument over Gomery's access to cabinet papers began in December.

It has centred mainly on a series of memos dealing with money that was channelled to the sponsorship program through a special national unity reserve fund personally controlled by Chretien.