Stewards want two stable employees who refuse to front the Aquanita bicarb inquiry temporarily banned from entering racecourses and training premises.

Greg and Denise Nelligan were stood down from their duties as stablehands after being charged as part of the investigation into seven years of alleged race day administrations of alkalinising agents.

The Nelligans will not take part in a Racing Appeals and Disciplinary Board hearing of their charges that begins on April 30, their lawyer Paul O'Sullivan told the tribunal on Thursday.

Racing Victoria stewards later issued show cause notices seeking to add restrictions on the Nelligans' racing activities as part of their standing down, pending the hearing and determination of the charges against them.

The rules allow a variety of conditions to be imposed on disqualified persons including a ban on entering racecourses and training premises and on receiving any direct or indirect financial benefit from thoroughbred racing or breeding in Australia.

The show cause hearing will be held on Monday.

Both Nelligans were employed by Group One-winning trainer Robert Smerdon and previously worked for trainer Tony Vasil, who was also charged.

Greg Nelligan and Smerdon were charged over more than 100 alleged race day treatments between 2010 and 2017.

Denise Nelligan was charged with being a party to the administrations on 13 occasions.