OTTAWA - The NDP is claiming a "clear victory" in a skirmish over evidence that will be heard in its ongoing satellite office legal drama with the House of Commons.

The Federal Court has spiked an appeal by a secretive all party committee, the attorney general and the Commons Speaker that sought to keep an affidavit out of the court hearing.

The affidavit, penned by a professor at the University of Sherbrooke, asserts that funding for satellite offices is not a matter of parliamentary privilege -- a key question at the heart of whether courts have jurisdiction in the dispute.

The legal battle over the NDP satellite office issue was launched after the Board of Internal Economy ordered 68 MPs -- many who were defeated in October's election -- to repay $2.7 million in parliamentary resources.

The board tried to prevent the affidavit from being entered into evidence, fearing it could undermine the privileges and immunities held by the Commons to deal with internal matters as it sees fit.

NDP Leader Tom Mulcair's chief of staff Raymond Guardia calls the court ruling a "clear victory" for the NDP.