The National Union of Journalists (NUJ) is planning protests outside STV’s Glasgow headquarters.
All Scottish news programmes on STV are expected to be cancelled on Wednesday as journalists stage a day of strike action.
The dispute is over compulsory redundancies and the end of a separate news service for the north of Scotland.
STV said the action was “ill-timed” as consultation with unions was ongoing.
Network programmes and advertising will not be affected by the strike.
It is also likely to mean a reduced news service on STV’s website.
But the company’s new music radio station, which opened on Tuesday, will remain on the air.
The National Union of Journalists (NUJ) is planning protests outside STV’s Glasgow headquarters and its Aberdeen offices.
Scottish organiser Nick McGowan-Lowe said members were striking in opposition to both compulsory redundancies and a management which he claimed “wanted to rip up” public service broadcasting obligations.
He said: “Viewers, staff, business leaders, politicians and unions all know STV’s plans are desperate, shortsighted, damaging to Scottish journalism and in complete disregard of the viewers and communities in the north of Scotland who depend on local coverage from STV News.”