Ministers have been criticised after a rail union announced a further wave of strikes just a day after agreeing a pay deal with the government.

Aslef, which represents train drivers, said the latest industrial action, which will see walkouts hitting LNER services on 22 days up until November, is in relation to a two-year dispute over their members’ working conditions.

It is unrelated to the 15% wage increase over the next three years which the union negotiated with transport secretary Louise Haigh.

Nevertheless, the timing of Aslef’s announcement is embarrassing for the government, which has pledged to end the strikes which have hit the railway network in recent years.

A Department for Transport spokesperson said: “This is extremely disappointing for passengers. The transport secretary has called on both Aslef and LNER to get around the table and work in good faith to resolve this dispute and as quickly as possible.”

Shadow Commons leader Chris Philp told Times Radio: “Clearly the Labour’s trade union paymasters have played them like a fiddle.

“The first rule of negotiation is if you make an offer, in this case a pay offer, you make sure that everything that needs to be settled and agreed is agreed at the same time. You don’t leave things undone, as this Labour government has clearly done.”

Tory leadership contender James Cleverly said: “The Labour government has been played by its union paymasters. This latest wave of strikes will be devastating for families who rely on train travel to see their loved ones.”

Aslef general secretary Mick Whelan said: “The continued failure of the company to resolve longstanding industrial relations issues has forced us into this position.

“We would much rather not be here. But the company has brutally, and repeatedly, broken diagramming and roster agreements, failed to adhere to the agreed bargaining machinery, and totally acted in bad faith.”

In a statement, LNER said: “Our priority focus will be on minimising disruption to customers during the forthcoming Aslef strikes, which sadly will continue to cause disruption and delays.

“We are surprised and disappointed to hear this news following recent constructive conversations. We will continue to work with Aslef to find a way to end this long running dispute which only damages the rail industry.”