Govia Thameslink Railway are warning customers about travel disruption across one of the busiest routes on its Southern Railway network over the next three consecutive weekends.

Passengers are urged to plan as the Brighton Main Line will be closed on 10/11, 17/18 and 24/25 January, with buses replacing trains between Purley / East Croydon and Gatwick Airport and between Reigate, Redhill and Tonbridge.

The line closure will allow a range of infrastructure works to be undertaken.

Including creation of a new road-rail access point in the Purley area, strengthening the cutting sides north of Merstham, along with improving the drainage systems around Caterham, and wheel timber installation on bridges near Godstone and Coulsdon South.

Track work will also take place. The conductor rails that supply power to the trains will be replaced between Reigate and Redhill, between Purley and Coulsdon South and around Stoats Nest Junction.

Running rails and points will also be replaced in the same areas, and also between Earlswood and Horley and between Coulsdon South and Merstham.

On the above dates, buses will replace trains on some routes, including Three Bridges to Gatwick Airport and East Grinstead.

Southern train services will still serve Gatwick Airport from Victoria and Clapham Junction, but will take a diversionary route, which will make journey times longer than usual. No Gatwick Express services will run, and cross-London Thameslink trains will terminate at East Croydon.

Passengers are also advised that Great Western Railway services from Reading to Gatwick Airport via the North Downs Line will also be affected by these line closures.

There will also be additional closures on the Brighton Main Line later in the year, affecting the Three Bridges, Brighton, Lewes and Hove areas.

These lines will be closed on Sunday 1st February, Saturday 21st and Sunday 22nd March, and Sunday 3rd May.

Looking further ahead through 2026, there are no engineering works planned on the Brighton Main Line during the busiest time of the year over the summer months. Though engineering works will take place during autumn and winter 2026.

“The busy Brighton main line is among the most complex and congested routes in the country, with the infrastructure being some of the oldest and most intensively used. Because of this, we need to carry out this work to try to prevent delays to passenger journeys.

We know that closing the railway at any time of the year causes inconvenience, but with the Brighton main line being a key route for the leisure and tourism industry on the south coast, we are using this typically quieter time on the railway to carry out these vital works, in an attempt to avoid having to close the railway during busier times of the year.

I’d like to thank passengers for their patience and understanding while our teams work hard to improve the infrastructure on this critical stretch of railway.”

Lucy McAuliffe, Network Rail Sussex route director