Some Southeastern services are facing delays due to flooding in a tunnel under the Thames.
It is causing a signalling problem which is also affecting Eurostar.
Delays of up to 50 minutes are expected on trains travelling in both directions between Stratford International and Ebbsfleet International.
Rail staff are working on removing the water.
Southeastern posted on X: “The signalling problem has been caused by flooding in one of the tunnels under the Thames.
“Unfortunately this means trains in both directions between Stratford International and #EbbsfleetInternational are having to use one line.
“Delays of up to 50 minutes are expected.”
At 1.32pm the rail company added: “Services between #EbbsfleetInternational and St Pancras are severely disrupted.
“We would advise using alternative routes into London via London Bridge, Cannon Street or Charing Cross if possible.
“Tickets are being accepted on the Underground on reasonable routes.”
Izzy Taylor, who is on one of the services, wrote on X just before 1pm that only one Eurostar train had gone through the tunnel in 45 minutes.
It follows a yellow weather warning being issued for Kent as 75mph winds are expected to hit the coast.
The Met Office alert stretches across the south of England and is in place from 11am on Saturday to 3am on Sunday.
More as we get it.