A third UK rail union announced strike dates for early October, with the period set to bring the worst disruption so far in months of walkouts in the industry.

The Transport Salaried Staffs’ Association said Friday that thousands of ticket office, station and control-room workers will walk out on Saturday, Oct. 1, the following Wednesday and Thursday, and again the next Saturday. Unions are seeking higher pay amid soaring inflation, as well as deals on job security.

TSSA, whose action will affect Network Rail Ltd. and 11 train operating companies, joins the National Union of Rail, Maritime and Transport Workers and drivers’ union Aslef in announcing a new wave of strikes after walkouts planned for last week were canceled on the death of Queen Elizabeth II.

All three unions are striking on Oct. 1, limiting travel options to the Conservative Party’s annual conference, which starts the following day in Birmingham. Two of the unions are also targeting Oct. 5, when delegates and other attendees will be making their way home from the event.

Prime Minister Liz Truss this week called on railway employees to end their action and “get back to work,” while saying she aims to take a “constructive approach” to the dispute after ministers under her predecessor Boris Johnson insisted that it was solely a matter for employers.

TSSA was also critical of a mini budget set out Friday by Chancellor Kwasi Kwarteng, saying moves to require pay offers to be put to workers during labor talks amount to “draconian” anti-union laws which will “elongate disputes.”