The vote at the Scotland-London train operator comes as travellers face an 11th RMT walkout at ScotRail tomorrow over downgrading conductors, or guards, on new trains.
Nearly 2,000 Vtec staff will be balloted, including “train managers”, or guards.
A union spokesman warned: “Action would lead to wholesale cancellation of services”.
The RMT said the vote was over concerns jobs would be cut because Vtec, which is 90 per cent owned by Perth-based Stagecoach, had overbid for the franchise.
The company, which operates between Edinburgh, Aberdeen, Inverness, Glasgow and London, has repeatedly denied the allegation.
The RMT claimed Vtec had failed to assure it there would be no compulsory redundancies, pay rates would be protected and guards would remain on trains.
The guards issue is at the centre of both the ScotRail dispute, and another one at Southern, south of London, which has led to large numbers of trains being cancelled.
The TSSA union also claimed 46 Vtec travel centre and station staff jobs will be lost, including in Edinburgh.
It said a strike ballot “cannot be ruled out”.
The RMT ballot will close on 9 August, with one week’s notice required for any industrial action.
A union spokesman said: “The company has chosen to ignore the agreed negotiating machinery and subjected staff to a barrage of direct propaganda justifying their attempts to bulldoze through a package of cash-led measure that would decimate jobs, working conditions and threaten the safety regime that currently ensures a guard on every train.”
Vtec said there would be no forced job cuts, and any action would not affect passengers.
A spokesman said: “We have big plans, with £140 million of investment. The on-board changes are part of them.
“We are puzzled by the RMT’s decision to ballot, as we have ruled out compulsory redundancies.
“A strike would also cost our people pay for no reason.
“We have well-prepared contingency plans which mean we expect to run a full timetable.”
Vtec would also consult staff over any travel centre changes.