Around 1,000 construction workers at the Heathrow airport terminal 5 site struck for two days before Christmas.
The workers, employed by the contractor Laing O’Rourke, are members of the GMB, T&G and Ucatt unions.
Laing O’Rourke employees are seeking an additional £1 per hour on their bonus scheme which has not been reviewed in three years and is lagging behind other workers on site.
This would increase their earnings, including the travel element, by roughly 5 percent. The last offer of an additional 22p an hour was rejected earlier this month.
Further strikes are scheduled for 20 and 23 January.