LISBON –

A three-day strike by workers at Lisbon airport led to the cancellation of several flights over the weekend, with more likely before the action ends on Sunday, the workers' union and Portuguese airport authority said.

EasyJet, Brussels Airlines, Eurowings, Transavia France, and Wizz Air UK flights from and to Britain, France, Belgium, the Netherlands, Luxembourg, Switzerland and Germany were cancelled on Saturday and Sunday.

SINTAC union spokesman Fernando Simoes said 19 flights had been canceled due to the strike, with seven redirected to Faro airport in the south of Portugal.

Portugal's airport authority's website showed more than 25 flights to and from the airport had been canceled.

A Lisbon airport spokesman declined to confirm the number of cancellations, but said a statement would likely be given at the end of the day.

Talks between SINTAC and Vinci Group-owned Portway, which employs workers at Lisbon, Porto, Faro and Funchal airports, broke down in December when the company said it would not unfreeze salaries.

It had committed to do so by November 2019 when the freeze was implemented in 2016.

Portway said in a statement on Sunday that it was ready to return to the negotiating table, with discussions already scheduled for January.

However, SINTAC spokesman Fernando Simoes told Reuters that the union plans to carry on with another strike by overtime and weekend workers from Jan. 1 to the end of March.

SINTAC said the company's decision not to unfreeze salaries was intended to punish the union's rejection of a revised work contract put forward by Portway in August.

"For three years workers have seen their career progression and salaries frozen for the sake of the company's financial health," they said on Friday.

Portway denied the allegations, Lusa reported on Friday, stating that they "scrupulously comply with regulations, including in relation to labor law.