It's an old saying among lawyers that in court, you never ask a question that you don't already know the answer to.

So I have to wonder what answers Stephen Harper's legal team are confident they already know:

Prime Minister Stephen Harper's legal team plans to ask a judge to summon B.C. author Tom Zytaruk to Ottawa to testify in Harper's defamation suit against the Liberal party over bribery allegations in the Chuck Cadman affair.

The Vancouver lawyer for Zytaruk and a Toronto lawyer representing the Liberal party confirmed Thursday that Harper's lawyer has signalled he wants Zytaruk to appear personally to attest to the authenticity of a recorded interview of Harper that is at the centre of the lawsuit.

Personal testimony in a libel suit would be unusual, even more so if the witness is from another province, [Liberal Party lawyer Chris] Paliare and Zytaruk's counsel, Vancouver lawyer Barry Gibson, both told The Canadian Press.

Gibson confirmed Zytaruk is aware of the possibility, and also confirmed Zytaruk has refused to furnish Dearden with an original copy of the recording for verification by audio and computer experts.

"For obvious reasons, Mr. Zytaruk doesn't want to give up the originals, especially to [Harper lawyer Richard] Dearden," Gibson said in an interview.

The actual appearance, if it happens, would take place in September.  But these legal moves will continue to apply pressure on the Liberals to settle.

Especially if the Liberals are nervous about what Zytaruk will say under oath, or what the original tape will show.