Train drivers at 12 rail companies are to target Liz Truss’ first Conservative Party conference as prime minister by going on strike.
The industrial action by the Aslef union is due to take place on October 1 and October 5, as part of a long running dispute over pay.
Tory MPs and thousands of party members are due to gather in Birmingham from October 2-5.
The strikes will therefore disrupt those travelling to the annual gathering as then going home afterwards.
Truss is due to deliver her keynote address to the conference at Wednesday lunchtime.
The RMT union also confirmed its own strike across the rail network on October 1, saying: “We will not rest until we get a satisfactory outcome.”
The 24-hour action which will bring the railway to an effective standstill and will come amid a wave of other strikes.
RMT general secretary Mick Lynch said: “Transport workers are joining a wave of strike action on October 1st, sending a clear message to the government and employers that working people will not accept continued attacks on pay and working conditions at a time when big business profits are at an all-time high.
”The Summer of Solidarity we have seen will continue into the Autumn and Winter if employers and the government continue to refuse workers reasonable demands.
“We want a settlement to these disputes where our members and their families can get a square deal. And we will not rest until we get a satisfactory outcome.”
A planned strike by drivers on September 15 was called off as a mark of respect following the Queen’s death.
Industrial disputes in the rail industry and other sectors, including post and telecoms, have led to a summer of strikes, which are set to resume in the coming weeks.
HuffPost UK revealed last week that the Tory conference is going ahead despite suggestions it could be cancelled due to the death of the Queen.
Labour’s conference at the end of September is also going ahead. But the Lib Dems cancelled their meeting as it coincided with the Queen’s funeral on Monday.
Conservative sources said the party is planning “a number of things” to mark the Queen’s passing.
It is understood they will include a minute’s silence, as well as the playing of the national anthem.