Along with the cost of tickets and punctuality, packed carriages on the service from Paddington to Temple Meads has long been a major grumble for commuters and passenger groups, with first-class carriages often nearly empty.
But the train company is hoping that the deal struck with the Government will go some way to dealing with the issue that appears to cause more complaints than most. First Great Western has been speaking to the Department of Transport about the problem of over-crowding and came up with solution.
The deal will create almost 3,000 more standard seats a day for travellers on the service. The arrangement will also see an increase of just under 16 per cent of standard-class seats in and out of London.
The increase in seat numbers is on top of extra peak-time seats made available last summer. The extra seats were made available by rebuilding and upgrading of disused buffet cars.
First Great Western managing director Mark Hopwood said: "We know that, ultimately, the only long-term solution to busy services is more trains.
"New IntercityExpress trains are on their way, however, it is still some time before they will be ready for service.
"The conversion of these carriages to create more standard class seating is crucial in the interim period."
But the shift will not see an end to first class travel. Work is being carried out to upgrade and improve the remaining first class carriages.
Each train will have one-and-a-half carriages set aside for first class. The improvements will include realignment of single seats, installation of privacy screens, more comfortable headrests, re-covered seats, new carpets and other changes.
The first completed carriages are expected to be running in June, with the entire fleet completed by late summer 2015.
The programme to provide additional standard class seats is being funded by the Department for Transport, while the changes to first class accommodation will be paid for by First Great Western.
Transport minister Patrick McLoughlin has been negotiating changes to the franchise agreement with First Great Western for several months.
Normally, a nine-carriage train will provide 101 first class and 526 standard class seats. A first class carriage has 50 seats, 35 fewer than in standard carriages.