PASSENGERS face widespread disruption when staff at more than a dozen rail companies go out on strike.
Transport for Wales will not be taking part in the industrial action, but three days of strikes by some union members at Network Rail - which runs the UK's rail infrastructure - mean there will still be problems for journeys in Wales.
Network Rail owns and maintains the majority of the country's tracks, bridges, tunnels and signal boxes.
This means Transport for Wales "will be unable to operate our rail services on Network Rail infrastructure", the firm said.
The majority of rail services across the Wales and Borders network will be suspended, with the exception of services on the Core Valley Lines north of Radyr, near Cardiff.
Transport for Wales said "there is also expected to be disruption on the days prior and after the industrial action".
And 13 rail firms in England, including Great Western Railway (GWR), will also be hit by the strikes, meaning further disruption for many Welsh passengers travelling over the border.
The disputes are over pay, jobs and pensions, with the union complaining that railway staff who worked through the pandemic are facing job cuts, a pay freeze and attacks on employment conditions.
The strikes threaten widespread travel disruption during a number of major events, including concerts, Test match cricket and the Glastonbury festival.
Glastonbury starts on June 22, while that week will also see England play New Zealand in a Test match in Leeds, the British Athletics Championships in Manchester, and gigs in London’s Hyde Park by Sir Elton John (June 24) and The Rolling Stones (June 25).
Talks between Network Rail and the union are expected to be held in the next few days, sources told the PA news agency.
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Network Rail is also drawing up contingency plans, with the strikes expected to cause disruption to services for six days, from the first walkout on June 21 to the day after the third strike.
Fewer than one in five trains are likely to run in areas affected, and only between 7am and 7pm, probably only on main lines.
No direct talks are planned between the union and train operators, although the RMT said it is open to “meaningful negotiations” to try to resolve the dispute.
In parliament, Boris Johnson described the plans for industrial action as “reckless and wanton”, and Downing Street later said it was working with industry on contingency plans to mitigate against the effects of the planned rail strikes.
The Labour Party, meanwhile urged the UK Government "to play a more active role in working with Network Rail and the unions to ensure [the strikes] don’t go ahead".
Additional reporting by Alan Jones, PA industrial correspondent
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