The Fair Work Commission's long-awaited decision on whether to cut weekend penalty rates in retail, hospitality and fast-food industries will be handed down on Thursday morning.

President Iain Ross advised parties today that the special five-member full bench, which he heads, will deliver its ruling at 11am at the commission's offices in Melbourne.

The commission is considering employer bids to reduce Sunday rates to the same level as Saturday rates, as recommended by the Productivity Commission, on grounds that they were "anachronistic" and affecting employment.

Fair Work Commission president Iain Ross has advised parties the commission is ready to release its penalty rates decision after two years of evidence. Alex Ellinghausen

The commission, which has been hearing evidence in the case since 2015, was expected to reach a decision by the end of 2016 but has repeatedly delayed its ruling.

The delays have fuelled insider speculation that the full bench has been divided on the issue, with one commission member saying that Mr Ross had warned commissioners a split decision would be a "public relations disaster".