Cambridgeshire commuters will face another day of strike action following disputes over rail safety.
Rail Union RMT says they have been left "no option" but to continue its strikes after an on-going row about the role of train guards on Greater Anglia services.
The RMT union claims driver-only operated trains are a threat to passenger safety.
Strike action is planned for Saturday, May 5 the same day as the iconic 2,000 Guineas race in Newmarket.
A further 24-hour walkout on Wednesday, May 9 is also planned.
RMT General Secretary Mick Cash said: "Yet again the intransigence of private rail companies operating in England over the key issue of the guard guarantee means that we have no option but to announce further strike action in the separate disputes on Arriva Rail North, Greater Anglia and South Western Railway."
"With RMT members protesting outside Parliament today we are drawing attention to the ludicrous situation that means we are able to reach agreements in Wales and Scotland on the guard guarantee but not on a raft of key franchises in England.
"If its good enough for Wales and Scotland to put rail safety first then it should be good enough for the rest of Britain.
"We have long detected the dead hand of the Government interfering to stop us reaching negotiated settlements in the current disputes and its about time Chris Grayling stopped playing politics with passenger safety and started taking the issue seriously.
"RMT remains available for genuine and meaningful talks in each of these disputes."
When are the strikes?
RMT members on Arriva Rail North, Greater Anglia and Southern Western Railway will strike for 24 hours on Wednesday, May 9.
Members on South Western Railway will also strike for 24 hours on May 11, May 14, May 16, and May 18.
What's actually happening?
The train operators are seeking to extend Driver-Only Operation (DOO) across its network, saying job numbers will not be affected.
But the RMT union claims driver-only operated trains are a threat to passenger safety and want guarantees over the role of guards.
Any possible strike is likely to affect rural services on the Greater Anglia network, including those travelling between Norwich and Ipswich to Cambridge.
Greater Anglia currently has 222 conductors and seven conductor managers on its network.
These train guards play a customer service role, giving advice and checking tickets. They also currently close train doors.
Greater Anglia is proposing that drivers will take over from conductors in closing doors on all of its trains.
DOO exists on 60 per cent of Greater Anglia trains and it wants to implement the practice across the whole of the network to encourage guards to focus on assisting passengers.
What Greater Anglia says
When the strike on May 5 was announced, Jamie Burles, Greater Anglia Managing Director, said: “We are very disappointed that the RMT has announced a strike.
“In recent weeks, we have had constructive talks with RMT union officials and discussed at length a proposal which we hoped would result in an agreement with the RMT. Unfortunately, the RMT has now decided to discontinue those discussions and announce a strike day.
“Our position remains the same: we highly value our conductors, were keeping them on our trains, but we want them to concentrate on customer service rather than opening and closing doors. We will continue to attempt to talk to the RMT to try to find an acceptable solution.”