Iberia's ground crew will go ahead with planned strikes at Barcelona's El Prat airport on Aug. 30-31, trade union UGT said on Wednesday, only a few hours after suggesting the stoppage could be called off.

The Spanish union said earlier on Wednesday it would cancel the strike to avoid delays for passengers during the peak holiday season and to facilitate ongoing talks with Iberia over working conditions.

But UGT spokesman Omar Minguillon told reporters that this plan had collapsed after Iberia would not accept the formation of a monitoring committee by the local government.

Spanish flag carrier Iberia, part of British Airways owner International Airlines Group, said in a press release on Wednesday evening that any monitoring committee would need to include other union groups or risk violating the existing collective bargaining agreement.

Strikes last weekend caused the cancellation of more than 350 flights, affecting more than 35,000 passengers flying on various airlines, the union said. Iberia's ground crew also serve a number of other airlines, including Barcelona-based Vueling.

El Prat is Spain's second-largest airport and sees a significant increase in traffic in summer.