Technicians and engineers working for BBC TV news are staging a 24-hour strike in a move aimed at hitting coverage of the state opening of Parliament on Wednesday.
Broadcasting workers' union Bectu said the walkout by almost 100 members from 10pm on Tuesday will affect the BBC's coverage of the event.
Further industrial action will be taken on November 23 and 24, although Bectu has yet to announce what form it will take.
The dispute flared after the union accused the BBC of changing established rotas and tearing up local agreements.
National official Luke Crawley said the strike would disrupt live news programmes on BBC1 as well as output on BBC News 24.
"We are targeting coverage of the state opening of Parliament and we are hoping to cause problems."
A BBC spokeswoman said: "We have contingency plans in place and we will do everything we can to minimise disruption to viewers."
