A train company has refused to open up first class carriages despite strikes causing “dangerous” overcrowding and pregnant women being forced to sit on the floor.

South West Railways (SWR) said its policy that decisions to declassify first class seats are down to the discretion of train guards currently remained in place despite the walkout.

Meanwhile, yesterday passengers complained that first class carriages were empty while commuters crammed onto “packed trains”.

One passenger, who is five months pregnant, called on the company to automatically declassify first class carriages for pregnant and disabled people, after she had to sit on the floor for 45 minutes because she could not find a seat.

It comes as the Rail, Maritime and Transport (RMT) union embarked on 27 days of strike action on Monday - the longest walkout against on a major operator in living memory.

The walkout has forced SWR to cancel around 850 trains - almost half of its timetable - running to and from London Waterloo, which is the busiest station in the country.

SWR has brought in 250 temporary workers to replace striking staff but the reduced service has led to severe overcrowding at peak times.

Mother-to-be Dani West, told The Telegraph she now “dreaded” her morning commute and was experiencing panic attacks as carriages had become so crowded.