Five Victorian trainers will face stewards to show cause why their licences should not be suspended pending hearings into the long-running cobalt affair.

The training partnership of Lee and Shannon Hope will be the first to appear before stewards on Wednesday after being charged on June 11 over elevated cobalt readings.

They will be followed by Peter Moody, Danny O'Brien and Mark Kavanagh.

The trainers have been charged after horses in their care returned levels above the threshold of 200 micrograms per litre of urine in raceday samples.

The Hopes will appear before the Racing Appeals and Disciplinary Board in October 15 to answer charges but no dates have been set for the other three trainers.