Train drivers are set to go on strike again, including on the day of the FA Cup final, as part of the long-running row over pay.
On June 3, members will strike on May 12 and May 31 and walk out on May 12 and May 31.
The union announced the move after it rejected a fresh offer from 16 train companies that included a 4% pay rise for two years in a row as well as changes to working conditions.
The latest strike is expected to cause major disruption across major areas of the country's railways and follow months of large-scale rail strikes in recent months.
Mick Whelan, the general secretary of Aslef, said the fresh offer from the train companies, which are presented to the union by the Rail Delivery Group on Wednesday, was risible.
The blame for this action lies, fairly and squarely, at the feet of the employers who have forced our hand over this by their intransigence, Mr Whelan said.