Rail passengers are facing three days of disruption as workers at five rail companies stage go on strike in separate disputes over staffing, driver-only operation and guards.
Members of the Rail, Maritime and Transport union (RMT) at South Western Railway (SWR), Arriva Rail North (Northern), Merseyrail and Greater Anglia are staging 24-hour walkouts on Monday, Wednesday and Friday.
Southern staff are also taking industrial action on Monday.
Talks have been held between the union and SWR and Arriva, but they have ended without any breakthrough to the long-running disputes.
RMT general secretary Mick Cash said: "Every single effort that RMT has made to reach negotiated settlements in these separate disputes with the different train operating companies over safe operation and safe staffing has been kicked back in our faces and we are left with no option but to press ahead with the action.
"No one should be in any doubt, these disputes are about putting the safety of the travelling public before the profits of the private train companies."
The disruption to services is as follows:
:: Northern says it will run around 1,350 services on strike days, more than half its normal timetable, with most running between 7am and 7pm.
:: SWR plans to run more than 70% of its normal weekday service of 1,700 trains, although there will be rail replacement buses and arrangements to have tickets accepted on other train companies.
:: Greater Anglia plans to run a normal service with no alterations.
:: Merseyrail will run a reduced service, mostly between 7am and 7pm, with a break during the middle of the day and no trains on the Kirby, Ellesmere Port or Hunts Cross lines.
Arriva Buses will accept Merseyrail tickets on all three strike days covering the Northern and Wirral lines.
Southern, which is facing its 39th RMT strike today, plans to run a normal service on most routes, but advised passengers to check for any last-minute changes before they travel.
Mr Cash, of the RMT, has written to Transport Secretary Chris Grayling proposing a summit with the Department for Transport, the train companies and the union.
The RMT said the meeting could consider how the principles of the agreements the union has reached in Scotland and Wales, which will keep guards on new trains, can be applied to the current disputes while meeting any concerns the Department for Transport and train companies have about future train services.
Shadow transport secretary Andy McDonald called on Mr Grayling "to take up" the proposal for a summit "in the interests of passengers".
A Department for Transport spokesman said: "This is a dispute between a private company and the RMT.
"However, the Transport Secretary recognises the disruption caused to passengers and has met with union leaders on several occasions, including as recently as December, to help bring an end to the strikes.
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"He offered guarantees of employment to members who currently fulfil the role of the second person on the train beyond the length of the franchises – instead the RMT called strikes on five train companies to cause maximum disruption to passengers.
"Nobody is losing their job as a result of driver-controlled operation trains – employees have been guaranteed jobs and salaries for several years."