The transport secretary tweeted that passengers using Avanti West Coast services should expect disruption on Sunday due to unofficial strikes. Ashlef said he was not promoting any industrial action on Sunday and said the lack of service was due to a lack of drivers. Shapps tweeted: “UNOFFICIAL STRIKES: Passengers using Avanti West services should expect disruption today. Archaic rules from 1919 mean that work on rest days is voluntary. Unions are now stopping volunteer drivers – causing misery to the public and staff who won’t be paid. We MUST modernize the railways.” Mick Whelan, general secretary of Aslef, responded to the tweet, saying: “Grant Shapps is a liar. He is not only wrong, he knows he is wrong. “His tendency to lie is just one reason why he was unable to muster enough supporters to get on the ballot to become Tory party leader. That and the fact that he’s not very good at his job. “The truth is that the company does not employ enough drivers to offer the services it promises passengers that it will perform. The company and the minister should stop lying and start hiring.” Avanti West Coast said it had previously always had volunteer overtime staff to cover weekend shifts for around 250 trains – with a “reservoir of highly reliable drivers” willing to do so. “We have a long-standing agreement with drivers to work shifts as overtime,” a spokesman said. “Literally overnight, the number for this week dropped to less than 10 trains covered by overtime. The drivers have, en masse, withdrawn their volunteering.” The company’s spokesman said it was now experiencing “multiple short-notice cancellations” on its network since Monday and that the cancellations are likely to continue until the current industrial dispute is resolved. “We regret the huge disappointment and inconvenience this will cause our customers and we condemn the actions of the drivers. We urge them to engage in meaningful conversations around modernizing working practices and developing a railway fit for the 21st century,” they said. Subscribe to First Edition, our free daily newsletter – every weekday morning at 7am More strikes are planned for August by Ashlef, the RMT union and the TSSA in escalating disputes over pay, jobs and conditions. Aslef members at Avanti will strike on August 13 as part of the long-running dispute over pay and conditions, but the union said no action had been taken until then. Whelan has previously accused Shapps of lying about negotiations over this summer’s rail strikes after Shapps claimed the RMT was “stopping on reform” and that Aslef was “dragging his feet in negotiations”. Whelan said Saturday’s strikes had been seen consistently and showed the strength of support. “This shows the solidarity of our members and their determination not to be pressured by Grant Shapps, the Department for Transport and the train companies. “Having kept Britain moving during the pandemic, they expect our members, who have not had a pay rise since 2019, to continue working, effectively for a pay cut.”