Workers at Heathrow Terminal 5 will strike if a wage agreement is not settled with the Electrical Contractors Association (ECA).

Union officials are visiting sites across the country to test workers’ appetite for industrial action over the ECA’s reluctance to renegotiate the Joint Industry Board (JIB) wage agreement.

On Tuesday, an informal meeting at T5 found that workers from the Unite-Amicus union would be broadly supportive of a strike if a new deal was not struck with the employers.

A source said: “They were 100% for strike action. BAA are very scared about this. It’s the best place to target strikes, because it’s the most high-profile project in the country.”

Workers on large projects in central London were due to meet on Thursday.

Unite-Amicus members rejected the JIB wage agreement in July. It is believed that the ECA will consider its position if workers do not accept the agreement by 13 September.

Work on the construction of a hotel at T5 was disrupted briefly on Tuesday when a Laing O’Rourke telehandler overturned. Nobody was hurt, and the accident is being investigated.