Train drivers have announced two more strikes as part of a long-running dispute over pay and conditions.
The Aslef union said its members at 16 train companies in England would walk out on 30 September and 4 October.
It added an overtime ban for drivers would take place on 29 September and for five days from 2 to 6 October.
The industrial action also coincides with the Conservative Party conference, which will be held in Manchester from 1 to 4 October.
Services are expected to be cancelled and cause disruption on the strike and overtime ban days.
Transport Secretary Mark Harper described the latest strikes as "cynical" and "politically motivated".
Both the train drivers' union Aslef and the RMT, which represents other rail workers, have been locked in a row with train companies over pay and working conditions, leading to regular strikes in the past 18 months.
Progress in the dispute with union bosses has ground to a halt since the latest proposals put forward in the spring by train operators were rejected.
The offer put forward included a series of changes to working practices which would enable pay rises of 4% for one year and 4% the next.
Mick Whelan, general secretary, said while the union regretted striking again, "the government, and the employers, have forced us into this position".
He said the union's members had not had a pay rise since 2019 which was "not right when prices have soared in that time".
"Train drivers, perfectly reasonably, want to be able to buy now what they could buy four years ago," he added.
In 2021, the median salary for train drivers was £59,189 per year.
The 16 companies affected by the latest strike action are Avanti West Coast, Chiltern Railways, c2c, CrossCountry, East Midlands Railway, Greater Anglia, GTR Great Northern Thameslink, Great Western Railway, Island Line, LNER, Northern Trains, Southeastern, Southern/Gatwick Express, South Western Railway, TransPennine Express, and West Midlands Trains.
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The Rail Delivery Group, which represents train companies, said it wanted to give staff pay rises, but said a deal was linked to "implementing necessary, sensible reforms that would enhance services for our passengers".
"The union have rejected a fair and affordable offer without putting it to their members," a spokesperson said.
"We ask the Aslef leadership and executive to recognise the very real financial challenge the industry is facing and work with us to deliver a more reliable and robust railway for the future."
Aslef's Mr Whelan compared Transport Secretary Mr Harper to "Where's Wally?", claiming he had not made contact with the union since December last year.
"Where's Mark Harper? He holds the purse strings. The train companies have told us. They say they cannot act without his say-so."
He called on Mr Harper to "come to the negotiating table" to end the dispute.
In a post on X, formerly known as Twitter, Mr Harper said the strikes train drivers were "paid an average of £60k for a 35-hour, 4 day week".
"There's an offer on the table to take that up to £65k - and still they strike, putting their own jobs at risk," he added.
The Department for Transport said the government had "facilitated fair and reasonable offers to both RMT and Aslef".
"Further strike action will not only put a strain on taxpayers, but risk driving passengers away from the network for good. These strikes will not prevent the need for essential workplace reforms," a spokesperson said.