Wales' busiest rail company is urging customers not to travel by train during the strikes next week as only two services will actually be able to run. The strikes are currently planned for June 21, 23 and 25, with disruption expected across the whole of UK's rail network.
Transport for Wales staff are not involved in the strike action, but services here will be affected because Network Rail staff are.
That is why the company says passengers should not travel by train on June 21, 23 and 25, and only if essential on June 20, 22, 24 and 26.
Read more: Rail strike map reveals train lines affected by train staff walkout
The only services in Wales running on 21 and 23 June will be a reduced service between Radyr and Treherbert, Aberdare and Merthyr Tydfil, with replacement bus services between Radyr and Cardiff Central.
On 25 June, this will be reduced further to services between Radyr and Treherbert, Aberdare and Pontypridd, with replacement buses in operation between Radyr and Cardiff Central, and between Pontypridd and Merthyr Tydfil due to the ongoing transformation work for the South Wales Metro.
All other services will be suspended, as signalling and other infrastructure work is managed by Network Rail, who are impacted by the industrial action.
There is also expected to be disruption on the days prior and after the industrial action, with early morning services in particular likely to be affected.
Network Rail Wales and Borders said it believed next week would be "tough" for passengers.
"This planned strike action means we simply can't run the vast majority of passenger and freight services as we will have fewer specialist signallers available," a spokesman said.
"Transport for Wales is not in dispute with rail unions, but its trains will be severely impacted as we rely on each other to provide services for passengers across most of Wales and Borders.
"The line between the Severn Tunnel and Cardiff will remain open with a very limited timetable. Transport for Wales is providing a shuttle service on the parts of the core Valley lines network it's solely responsible for."
A TfW spokesman said: "Trains are also expected to be extremely busy throughout the entire week.
"As a result, TfW is advising that customers only make essential journeys by train on 20, 22, 24 and 26 June, and not to travel at all by train on 21, 23 and 25 June."
Full details of the timetable for these days will be available from today (June 16). Customers can find these on the TfW, Traveline and National Rail websites using the journey planners.
Customers with existing non-season tickets valid for travel from Tuesday 21 June to Saturday 25 June can use those tickets anytime between Monday 20 June and Monday 27 June. Alternatively, customers can claim a full refund, with no admin fee charged. Season ticket holders can apply for compensation via Delay Repay.
In the meantime, TfW has suspended sales of Advance tickets for the first three strike dates in order to minimise the number of people disrupted. Customers are advised to continue to check the TfW or Traveline websites, and those of other operators, for updates.
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