BULLYING Southern Rail bosses’ union-busting tactics were branded disgraceful yesterday after they threatened to punish staff for taking lawful strike action.

A letter seen by the Star was sent to workers last week warning them that they face “individual sanctions” if they take part in any further action called by the RMT.

RMT general secretary Mick Cash blasted the letter as “disgusting dirty tricks,” accusing Southern Rail of “threats, bullying and intimidation” as the failing outfit puts profit ahead of public safety.