Mick Cash denies RMT is part of 'conspiracy to bring Government down'
The general secretary of the RMT has dismissed claims the union is "part of some conspiracy to bring the Government down".
Mick Cash has insisted train workers are staging a series of strikes this Christmas because they are worried about the safety of passengers.
He was forced to defend the RMT after its president, Sean Hoyle, reportedly said unions are coordinating strike action to bring down the Tory Government.
Appearing on BBC Radio 5 Live's Pienaar's Politics, Mr Cash said the strikes on Southern rail network are not a political stunt but over concerns about passengers being caught in doors, dragged along platforms and getting injured.
He said: "I see the media reports today, and as far as I'm concerned I'm not interested in what's said at fringe political meetings.
"We are a serious industrial trade union, we are not part of some conspiracy to bring the Government down. We are focusing on the concerns that our members have had around safety on the railways."
Unions are striking to keep guards in operation of the doors on trains, a role they say is crucial to the safe operation of the routes.
Mr Cash added: "That's what this dispute is about - it's all about safety and it's about us trying to ensure there is a guarantee of a second safety critical person on every train."
He accused Chris Grayling of "failing" as Transport Secretary because he is not helping to resolve the dispute, and urged him to "sort this out"
Mr Cash said the union does not relish taking strike action, but the alternative is to let the railways degenerate "into unsafe practices".
"Politicians come and go and I've seen a huge amount of secretaries of state in the last few years - there's been around 30 since privatisation" he said.
"They come and go, we are the people who actually pick up what they leave behind and we don't want to be in a position where we run an unsafe railway. And that's where they are going."