Former News of the World editor Andy Coulson will learn the result of his appeal against a High Court ruling that News Group Newspapers (NGN) does not have to pay his legal costs arising from the phone-hacking affair.
Coulson, 44, who resigned in February 2007, has sued NGN over the construction of a clause within a severance agreement.
He wants a declaration that the company, which stopped reimbursement in August last year, "must pay the professional costs and expenses properly incurred" by him "in defending allegations of criminal conduct" during his tenure.
At last December's High Court hearing, NGN's counsel told Mr Justice Supperstone that the clause covered the "occupational hazards of being an editor" and not alleged criminal activity.
It maintains that, if there is an obligation, it is triggered at the stage when proceedings are complete.
At the Court of Appeal earlier this month, three judges agreed to an application by Coulson's lawyers to admit fresh evidence on the appeal, relating to the criminal investigation.
This included material in the press, which NGN would neither confirm nor deny, that Rebekah Brooks and some current employees of the Sun appeared to have been indemnified in respect of some criminal proceedings as they went along, rather than waiting until the end.
Lord Justice Laws, sitting with Lord Justice Sullivan and Lord Justice McCombe, said: "We would propose to infer that other persons, notably Rebekah Brooks, are being funded as alleged in the new evidence, absent any contradiction to that proposition."
Coulson, who has always denied any wrongdoing, resigned from his position as Prime Minister David Cameron's director of communications in January last year, saying that coverage of the scandal was making it too difficult for him to do his job.