Workers at two sets of museums were set to strike over pay on Thursday of this week.
Members of the Prospect union at the Science Museums Group and Museum of London are fighting low pay.
Both sets of workers are rejecting paltry pay rises of just 1.5 percent, which is below inflation and effectively a pay cut.
Science Museum sites across Britain are set to strike for a second time.
The workers previously struck for one day at five sites owned by Science Museum Group—in London, Manchester, Bradford, York and Wiltshire—at the end of August.
And workers at Museum London and the Barbican and Dockland sites are set to walk out for half a day, also on Thursday.