The government's transport spokesman in the House of Lords has told peers he could not afford to buy the train fare from London to Birmingham.
Earl Attlee said same-day travel tickets could be very expensive.
He told peers: "One day I wanted to go to the NEC to visit the motor show and I could not afford the walk-up fare. Just too expensive for me."
The Conservative peer had come under pressure in the Lords to defend rises in rail ticket prices.
Passengers are facing their 10th consecutive year of above inflation fare rises, with the average season ticket increasing by 4.2%.
Overall, ticket prices have gone up by 3.9% in England, Wales and Scotland, but rises vary between train operators.
Earl Attlee said a recent survey by Passenger Focus had reviewed UK rail fares and, although the "overall picture was mixed", the country compared favourably with other European countries "in respect of many ticket types, particularly on longer distance tickets purchased in advance".
Labour peer Lord Campbell-Savours told Earl Attlee that tickets purchased on the day of travel "are invariably far more expensive that advanced travel tickets", and asked whether the European comparisons were based "on the former or the latter".
Earl Attlee said the cost of tickets bought in advance "compare well with our continental partners" but admitted that, as confirmed by his personal experience, this was not the case with same-day travel.