Air traffic controllers to strike across seven airports
The union members are in a dispute with Highlands and Islands Airports Limited over pay.
Air traffic controllers in the Highlands and Islands have announced three new strike dates across seven airports in a dispute over pay.
Prospect union members took industrial action in May and were scheduled to walk out again on June 12, but called off the strike after Highlands and Islands Airports Limited (Hial) put forward a new deal.
The deal was turned down last week, however Prospect and Hial met again on Thursday in a further attempt to resolve the dispute.
After Hial rejected Prospect's counter proposal, the union confirmed 24-hour strikes will take place at Inverness Airport on July 21, at Sumburgh, Kirkwall and Wick airports on July 22, and at Dundee, Stornoway and Benbecula airports on July 23.
The union members will also "work to rule", which includes an overtime ban, an instruction to work to rosters and the withdrawal of good will.
'We would like to reiterate that we have been seeking to resolve this dispute for more than a year and this action is only being taken as a last resort.'David Avery, Prospect negotiations officer
David Avery, Prospect negotiations officer, said: "While we will seek to avoid disrupting major events as much as possible, any strike action is disruptive by its nature, particularly during the school holidays.
"We would like to reiterate that we have been seeking to resolve this dispute for more than a year and this action is only being taken as a last resort."
A strike in April disrupted services at Inverness, Dundee, Benbecula and Stornoway in the Outer Hebrides, Sumburgh in Shetland and Kirkwall in Orkney.
Prospect claims members' pay has fallen significantly behind the rest of the industry due to public sector pay restraint.
The union is looking for a 10% pay increase.
Amid the dispute, a plane was forced to depart from Orkney to Edinburgh without air traffic control clearance.
The union argued that start-up clearance was denied as it would have involved a controller having to work beyond their shift - contravening "very strict" rest periods.
Hial, a public corporation wholly owned by Scottish ministers, previously insisted it was bound by government pay policy and could not negotiate a separate settlement.
However, the Scottish Government permitted Hial to develop a retention allowance in a bid to resolve the dispute.
'It is disheartening to have received a counter offer from Prospect that is beyond our affordability.'Inglis Lyon, Hial's managing director
In response to the industrial action, Inglis Lyon, Hial's managing director, said: "We are dismayed that Prospect has announced further days of strike action and apologise sincerely to our customers, passengers and local communities for the continued disruption.
"It is disheartening to have received a counter offer from Prospect that is beyond our affordability.
"Over the past eight months we have discussed various options with the union and have been clear throughout that any proposal must be affordable and within the terms of Public Sector Pay Policy.
"Prospect are aware of Hial's budgetary restrictions and our latest offer constituted compromise to accommodate trade union demands within the bounds of the pay policy.
"We remain committed to resolving the dispute and our latest offer of a retention allowance of £10,000 over a five-year period remains on the table.
"The continued industrial action is having a significant impact on our communities and the airlines operating from our airports. We would encourage Prospect to revisit the offer and bring this dispute to an end."