RAIL union RMT demanded urgent action to protect staff “caught in the crossfire” of continuing chaos at London Bridge station yesterday.

Botched planning for redevelopment work had already put services at the rail hub under strain, but signalling failures and a person on the tracks caused travel chaos last week and a broken down train delayed thousands again yesterday morning.

“Staff have been threatened, had hot coffee thrown over them and been spat at as passengers take out their anger on the workforce,” RMT said in a letter to rail operators Southern, Southeastern and Thameslink.

The union says planning for the Thameslink project was “flawed and input from employees and representatives was seriously lacking.

“Concerns raised by union members in advance were completely ignored.”

RMT is demanding increased staffing to deal with the morass.

General secretary Mick Cash said his members were “furious that they are taking the full force of the anger of passengers while those responsible are snug and warm in their offices.”