Image copyright PA Image caption Mick Cash said the Southern dispute was "all about safety"

The RMT is not using Southern rail strikes to try to "bring the government down", its general secretary has said.

Mick Cash told the BBC union members would "rather be at work", but had real concerns about safety on the network.

He spoke after the RMT's president reportedly said his union and others were co-ordinating strikes to hurt the "working class-hating Tory government".

Industrial action over changes to driver-only operated trains has led to severe disruption to Southern services.

It comes amidst other strikes by British Airways staff, airport workers and the Post Office due to take place over the next week.

What is the Southern row about?

Both Aslef and the RMT union are in dispute with Govia Thameslink over plans to remove the role of guards in operating train doors.

Mr Cash said he was "not interested" in RMT president Sean Hoyle's comments, which were reportedly made at a "fringe political meeting".

According to the Sunday Times, Mr Hoyle said the union's "number one rule" should be to "strike to replace the capitalist system with a socialist order".

The article quotes from a number of Mr Hoyle's recent speeches, including one given at a National Shop Stewards Network meeting in Brighton when he is alleged to have said: "Any trade unionist with any sense wants to bring down this working class-hating Tory government.

"That's what we want to do. That's what we're about."

Mr Hoyle also reportedly referred to a previous story which suggested the RMT and other unions were "co-ordinating to bring the government down", responding: "Shock horror. Guess what? We are."

Christmas industrial action

Crown Post Office staff - Monday 19 to Friday 23 December

Monday 19 to Friday 23 December British Airways cabin crew - 25 and 26 December

25 and 26 December Swissport check-in staff, baggage handlers and cargo crew - 23 to 25 December

23 to 25 December Virgin Atlantic pilots - work to rule from 23 December

Mr Cash told Pienaar's Politics on BBC Radio 5 live: "We are a serious industrial trade union, and we are not part of some conspiracy to bring the government down - we are focusing on the concerns our members have over safety on the railways."

He continued: "The person who speaks for the RMT is the general secretary, and that's me.

"This dispute is all about safety and not about bringing the government down."

Mr Cash said in February, Peter Wilkinson, the Department for Transport's director of franchise, told a meeting he was "going to take on the trade unions and get the unions out of his industry".

"Within days, we had proposals from Southern rail to get rid of the second, safety-critical, guard on their trains. So that's what this dispute is all about - it's all about safety."

'Think about impact'

The Department for Transport previously told the BBC the dispute was between Southern and the unions and "not something the government is involved in".

The Sunday Telegraph, though, is reporting that Prime Minister Theresa May is facing a "growing backlash" from Conservative MPs because she is reluctant to table any emergency legislation about rules governing when unions can take industrial action.

Labour MP Meg Hillier told Sky News' Murnaghan programme that although people were entitled to strike, the action was "very unfortunate".

"I think that all trade unions, even though they're fighting for their rights, need to really think about the impact on the people they're actually there to serve, their customers, or their passengers."

She added: "I think if they're not careful they could be shooting themselves in the foot."

Further strikes are planned by both unions: