I congratulate my hon. Friend Caroline Dinenage on securing this debate. I will do my best to address the points that she raised so eloquently. I apologise for being a poor substitute for the Under-Secretary of State for Transport, my hon. Friend Claire Perry, who has responsibility for rail. She is currently speaking in Westminster Hall, and even she cannot be in two places at the same time.

As my hon. Friend the Member for Gosport knows, the Portsmouth-to-London line is an essential artery that connects communities across Hampshire, Surrey and south-west London. As she said in her speech, it is not only up north that we need to deliver new jobs and prosperity on the back of infrastructure. She mentioned the problems following the cuts to defence jobs in her part of the world.

The railways are a success story of recent times. Passenger numbers have doubled across the country over the past 15 years to the same levels as 1929, but on a network that is half the length. South West Trains operates about 1,700 services a day and about 222 million passenger journeys were made on South West Trains last year. London Waterloo is the UK’s busiest railway station and Clapham Junction station, which is operated by Stagecoach South Western Trains, is the busiest interchange, with somewhere in the region of 23 million interchanges each year.

My hon. Friend is right to raise the issues of journey times and capacity on the route between Portsmouth and London. She mentioned the journey to Doncaster. I will be journeying to York this evening. That journey takes 1 hour and 50 minutes, which is not much longer than the journey down to Portsmouth. Indeed, if one includes the Gosport ferry, that journey takes much longer, even though it is over a much shorter distance.

There are issues of great concern for many passengers who use train services on the route from Portsmouth to London. Many travel for work, but people also travel for leisure, as Portsmouth offers many attractions for the visitor. That is not to mention the important connections to the Isle of Wight and to my hon. Friend’s constituency by the Gosport ferry, for which South West Trains will offer through fares from January. The provision of reliable rail services on the line is therefore enormously important for economic activity and growth along the route.

Nearly 7 million passenger journeys were made to and from Portsmouth stations during 2012-13. Investment has been made and continues to be made to improve the facilities at those stations through schemes such as the national stations improvement programme. Portsmouth stations are served by a number of train operators—South West Trains, Southern and First Great Western—meaning that Portsmouth is connected to much of the south of England and Wales. However, I agree that the speed of those journeys is somewhat slower than on other routes that connect our cities, with the 74-mile journey between Portsmouth and London Waterloo taking about 90 minutes. My hon. Friend will be aware that there are legitimate reasons for that, which must be borne in mind.

The Portsmouth main line is a two-track route between Portsmouth and Guildford, connecting the south coast to London. The route is powered by a 3rd rail DC supply, with a maximum line speed considerably lower than the 125 mph seen on East Coast or Great Western main lines, for example. The line speed south of Guildford falls below 90 mph to 85 mph or less—indeed, to only 40 mph in some locations—on many parts of the route, which is caused by gradients and curves in the line profile. Coupled with the relatively high number of stations at which the train calls along the route, that makes it difficult to increase the line speed of those services.

There are few places where faster trains can overtake slower ones. In the section between Guildford and Havant, the only location where overtaking is possible is at Haslemere. That is not to say that no thought has been given to improving those vital services. Although previous investigations into improving journey times have shown a high cost for minimal benefit, service frequency has been increased where possible. That has been of greater benefit to the large populations using the train service from stations along that route.

There is no quick fix, and I will not suggest there is. The Portsmouth mainline is full to capacity and South West Trains is already operating most peak services at maximum formation. There are constraints on infrastructure and rolling stock, and as we have heard, passengers face difficulties. I am not saying, however, that improvements are not possible, and with the right conditions, journey times can be improved and extra main line capacity added. It is vital that the necessary planning for such investment takes place, and that consideration is given to the needs of the railway as a whole, giving us options for how to meet the demand that is forecast to continue growing over the next 30 years.

The long-term planning process is designed to facilitate the strategic planning of the industry, taking into account the views of the rail industry, funders, specifiers and customers. Network Rail is publishing draft route studies for stakeholder consultation. The draft route study for Wessex is due to be published for consultation later this month. It will set out ideas and proposals for investment over the course of Network Rail control period 6, which runs from 2019 to 2024, and beyond.

Local authorities, including Portsmouth city council, have already had the opportunity to feed into that draft study. It is very much a collaborative process, and I am keen to see it continue. The route studies will be published on the Network Rail website, together with further information about the long-term planning process. I strongly encourage my hon. Friends and their constituents to embrace the opportunity to help us shape the future of that railway, in the collaborative spirit to which I alluded. It is incredibly important for those who use that part of the network to have a say in its future.