A general strike in Greece on Tuesday is followed by an international air traffic controllers' strike on Wednesday, and a day of strikes in Spain on Thursday.

Nearly half French flights are expected to be affected by Wednesday's industrial action, which will also hit Italy, Portugal, Greece, Hungary and Slovenia to a lesser extent.

For Italy this strike, in protest against EU plans for a Europe-wide air traffic system, known as Single Skies, is just the first of a series of strikes over the next week and a half.

Country by country the outlook is as follows:

• In Greece a strike directed against pension reform plans is expected to hit all government and public services. State health services and hospitals will be staffed by skeleton crews, and banks - already hit by separate industrial action - will suffer their fourth disruption in five days.

  Olympic Airways cancelled 31 domestic and international flights on Tuesday, but the European air traffic control body, Eurocontrol, predicts that Greece will not be seriously affected by Wednesday's stoppage.

• In France, by contrast, the national carrier says it will only be able to guarantee 10% of its domestic and European flights on Wednesday, as a result of the action by a federation of 13 European air traffic controllers' unions.

  While British Airways has cancelled all but four of its 126 daily flights to and from France on Wednesday, long-haul flights from France are expected to experience fewer problems.

• In Spain the government has ordered transport workers to maintain a minimum service during Thursday's general strike, but at a time of year when holidaymakers are pouring into the country, serious disruption is expected.

  The protest against unemployment benefit reforms could also affect officials and demonstrators travelling to the European Union's summit in Seville, which starts the following day.

• In Italy travellers face repeated problems as a one-hour air traffic controller's stoppage on Wednesday is followed by an eight-hour public transport strike in several cities on Friday, and a railway stationmasters' strike on Saturday and Sunday.

  Alitalia pilots have also said they will stop work for four hours on Friday 28 June in a protest linked to pay and conditions.

  Further transport strikes are planned in Italy for July.

The striking air traffic controllers believe the Single Skies system will lead to job losses and privatisation.

European Commission spokesmen have said this is a misunderstanding, and that the strike risks damaging European airlines just as they are beginning to recover from months of economic difficulties.