British train fares are the highest in Europe
The UK's first £1,000 rail ticket has been described as "scandalous" and "appalling value" by opposition MPs.
The first-class return walk-up fare is from Newquay, in Cornwall to Kyle of Lochalsh, in the Scottish Highlands.
The Conservatives blamed "Labour's micromanagement of the railways", while the Lib Dems called the record fare "a very unwelcome landmark".
Cross Country Trains, which sells the ticket, said an advance fare was available for £561.
The fare was unearthed in a survey by rail expert Barry Doe, who said that the price of long-distance journeys had risen by up the three times the level of inflation since privatisation in the mid-1990s.
Mr Doe told the Evening Standard newspaper that even the £1,002 ticket had been available for £486 as recently as September 2008.
Three train companies share the 1,700 mile (2,736km) return trip - First Great Western, Cross Country and Scotrail.
The £1,000 journey is from Cornwall to the Scottish Highlands
Mr Doe pointed out that on the first leg of the journey (Newquay to Par) and the last (Inverness to Kyle of Lochalsh) there were not even any first-class carriages for the ticketholder to sit in.
A spokesman for Cross Country said: "No-one has actually bought this £1,000 fare but it does exist.
"Someone wanting a first-class return would be likely to book a saver return in advance and pay £561."
'Takes the biscuit'
Cat Hobbs, from the Campaign for Better Transport, claimed the £1,000 journey showed "just how pricey and complicated the fare structure is".
And while regulated fares will actually fall slightly from January because of retail price deflation, she said she feared train companies would raise their unregulated fares to make up for the drop in their income.
"We think the government should step in and review how they regulate fares," she said.
"The government should not let the train companies take all the flak for this. It's up to the government to change the system."
Lib Dem transport spokesman Norman Baker said high fares were encouraging people to abandon the trains in favour of their cars.
And he added: "When you can fly halfway across Europe for £30, the idea that you can end up paying £1,000 for a train journey in Britain is absolutely scandalous."
Shadow rail minister Stephen Hammond said: "Due to Labour's micromanagement of the railway, farepayers have become all too used to appalling value for money.
"Today's revelation of a £1,000 fare really takes the biscuit."