A trial to simplify train fares is adding more than £100 to the cost of some journeys on one of Britain’s busiest railway lines.

The price hike was revealed by PA news agency analysis of tickets sold by Government-owned operator London North Eastern Railway (LNER) for travel on the East Coast Main Line.

This follows the introduction of a two-year trial advertised as offering “simpler fares”.

Campaign group Railfuture described the scheme as “awful”, while train travel website Seat61.com claimed it is designed to “allow big price increases”.

LNER pledged to “make adjustments so that as many people as possible can access the right ticket at the right price”.

Under the trial, the cheapest available tickets for some single journeys between London King’s Cross and Edinburgh have increased from £87 to £193.90 if purchased on the day of travel.

Similar rises were found for journeys between London King’s Cross and both Newcastle and Berwick-upon-Tweed.

The pilot, which was implemented earlier this month, is limited to those three routes but could be rolled out across the network if deemed successful.

The price hike has been caused by the removal of Super Off-Peak fares, which were the cheapest tickets that could be used on several departures during traditionally quieter periods without needing to be bought in advance.

PA analysed prices for services that could previously be travelled on by holders of those tickets, which cost between £83.80 and £87 depending on the route.

For some services booked on the day of travel the lowest priced available tickets are now fully flexible Anytime fares priced between £192.80 and £193.90.

Most services have cheaper options available – either fixed Advance tickets or new semi-flexible 70min Flex tickets – but in some cases these fares are more expensive than the Super Off-Peak prices.

Railfuture director Neil Middleton said: “The removal of the Super Off-Peak ticket is an awful move.

“Just the possibility or having to pay over £192 for a railway ticket to travel between King’s Cross and Newcastle is enough to put you off travelling by train, possibly forever.

“Yes, it is quite possible to travel for a lot less, but if you need to travel unexpectedly or travel plans change, these are eye-watering prices to pay.

“I think they are well beyond tolerable for most people’s wallets and indeed most companies’ expense claims.”

Mr Middleton said the flexibility offered by the 70min Flex fare is “a real benefit” but he expressed concern that “the ticket may not be available when I want to travel”.

He urged LNER to reinstate Super Off-Peak fares but continue with the rest of the trial.

The introduction of the scheme comes as train operators are under increasing pressure from the Department for Transport (DfT) to increase revenue in an attempt to reduce taxpayer-funded subsidies.

Mark Smith, founder of Seat61.com, said: “It’s now pretty clear to everyone that the LNER fares ‘simplification’ was a smokescreen for removing the Off-Peak fare to allow big price increases.

“I now suspect DfT is behind this.

“As a trial simplification for passengers it has already failed and should not be extended.”

He explained that people travelling from London King’s Cross to Edinburgh at short-notice could get a “better deal” if they buy an £87 Super Off-Peak ticket to Haymarket, one station beyond Edinburgh.

Those tickets – which are still available because Haymarket is not part of the trial – permit a break of journey, meaning passengers can end their trip at Edinburgh and save 55% compared with the £193.90 Anytime fare.

Guy Hobbs, travel expert at consumer group Which?, said: “It will be incredibly frustrating to passengers if a scheme proposed to simplify the ticket purchasing process is sneaking in price hikes by the back door.

“Super Off-Peak fares are usually the best value, so it’s essential that LNER looks at making changes to ensure this new scheme offers travellers equally competitive prices.”

An LNER spokesperson said: “Since the pilot launched, the majority of customers who have bought Advance tickets have paid less than the old Super Off-Peak fare.

“There will, from time to time, be traditionally classified ‘Off-Peak trains’ where Advance tickets have sold out and a more expensive Anytime ticket is the only option on popular services.

“However, the pilot will see even more Advance and 70min Flex tickets being available up to the day of travel.

“We’ll continue to monitor and will make adjustments so that as many people as possible can access the right ticket at the right price for them.”

The operator added that before the trial, the percentage of fares purchased on the routes that were Super Off-Peak was 11%.

It believes the new pricing system will more closely reflect demand and lead to fewer instances of overcrowding.

A DfT spokesperson said: “LNER’s trial is part of a long-standing commitment to simplify complicated ticketing which can often put people off taking the train.

“Through this, the majority of passengers on these routes will find fares to be the same or cheaper than the old Super Off-Peak fare.”