Virgin East Coast passengers can now bid for first class upgrades on an app minutes before trains leave

Rail passengers can now bid for an upgrade to first class seats minutes before their trains depart.

Virgin Trains East Coast has begun auctioning off empty first class seats through a smartphone app shortly before its services leave.

Prices start from £5 for a seat in first class carriages featuring complimentary food and drink, free wi-fi, reclining leather seats and extra legroom.

Upgrades are initially available on some weekday services from London King's Cross to Edinburgh, Leeds, Newcastle and York, with more routes expected to be added shortly.

Regular walk-up first class fares for London to Edinburgh journeys can cost almost £90 more than standard class tickets.

Each auction opens approximately two-and-a-half hours in advance and closes around half an hour before the train departs.

Suzanne Donnelly, commercial director at Virgin Trains East Coast, said: "We are really excited to be partnering with Seatfrog to offer customers more opportunities to experience first class.

"Passengers can get upgrades from as little as £5 and there are real deals to be had.

"The live bidding element means you can decide at the last minute if you fancy treating yourself."

​Seatfrog chief executive Iain Griffin said people wanting to guarantee first class travel should buy a regular ticket, as auctions will not be held for all trains.

He added that he is in discussions about rolling out the service with a number of other travel firms.

Passengers who want to use the system for a first class upgrade enter their booking reference into the app and start bidding.

Successful participants are instantly sent a new ticket direct to their smartphone or tablet.