Portsmouth to London Heathrow Airport (LHR) train

South Western Railway is a train operating company in the United Kingdom, providing services in the south and south-west of England. It operates a variety of train types, including high-speed trains, local stopping services, and suburban commuter trains. It also offers a range of ticket types, including Advance, Off-Peak, and Super Off-Peak tickets. Onboard facilities include free Wi-Fi, power sockets, and a range of food and drink options. The most popular routes for South Western Railway include London Waterloo to Portsmouth Harbour, London Waterloo to Weymouth, and London Waterloo to Bournemouth.

Southern Rail is a train company based in the United Kingdom. It operates a wide range of services, from high-speed intercity trains to local commuter services. Its trains include the InterCity 125, InterCity 225, and Class 444 and 450. It also offers a variety of ticket types, such as Advance, Off-Peak, and Super Off-Peak. Onboard facilities include free Wi-Fi, power sockets, and a range of food and drink options. The most popular routes for Southern Rail are London to Brighton, London to Southampton, and London to Portsmouth.

Cross Country trains are a UK-based train operator that provides services across the country including trains between Portsmouth and London Heathrow Airport (LHR). They offer a range of services, from express services to local services, and have a variety of ticket types to suit different needs. Their express services, such as the CrossCountry Voyager and CrossCountry XC Trains, offer a fast and comfortable journey, with onboard facilities such as free Wi-Fi, power sockets, and a selection of snacks and drinks. Their local services, such as the CrossCountry Regional and CrossCountry Regional Express, provide a more leisurely journey, with stops at smaller stations along the way. They also offer a range of ticket types, such as Advance, Anytime, and Off-Peak tickets, to suit different budgets and travel needs. The most popular routes for Cross Country trains include London to Birmingham, Manchester to Edinburgh, and Bristol to Reading.

Great Western Railway is a train operating company in the United Kingdom. It operates services from London Paddington to the West of England, South Wales and the Cotswolds. It also operates services from London Paddington to Oxford, Reading and Bristol. It offers a range of ticket types, including Advance, Anytime, Off-Peak and Super Off-Peak tickets. Onboard facilities include free Wi-Fi, power sockets, air conditioning and catering services. The most popular routes for Great Western Railway are London Paddington to Bristol, Reading and Oxford.