The premium carriages will offer more spacious seats and improved connectivity, but catering will not be provided.
This move marks a significant shift for Chiltern Railways, which had eliminated first-class seating over a decade ago and a business zone in 2020.
The reintroduction is primarily driven by the acquisition of new Mark 5A trains, which are already configured with first-class sections, making conversion to standard class financially unviable.
The new fleet, replacing older carriages, will also feature modern amenities such as plug sockets and enhanced Wi-Fi.